allison 2500

[pcdreams]

Do these have the lockup? Looking at a full size with DT466 that's suppose to have one of these. This could just be my lucky day.

[EastCoastCB]

Originally Posted by pcdreams

Do these have the lockup? Looking at a full size with DT466 that's suppose to have one of these. This could just be my lucky day.

Lockup AND overdrive.

I've got a bus with a 466/2500 and its SWEET.

[Pizote]

The 2500 comes in 5 and 6 speed models with both lockup and overdrive as EastCoastCB has stated. They are basically the same transmission with a software unlock. Both 5th and 6th gears are overdrive. Here's the ratio chart.

First 3.51 : 1
Second 1.90 : 1
Third 1.44 : 1
Fourth 1.00 : 1
Fifth 0.74 : 1
Sixth 0.64 : 1
Reverse -5.09 : 1

Even better, here's the spec sheet on them: https://www.allisontransmission.com/...rsn=877fbf1c_2

[cadillackid]

Originally Posted by Pizote

The 2500 comes in 5 and 6 speed models with both lockup and overdrive as EastCoastCB has stated. They are basically the same transmission with a software unlock. Both 5th and 6th gears are overdrive. Here's the ratio chart.

First 3.51 : 1
Second 1.90 : 1
Third 1.44 : 1
Fourth 1.00 : 1
Fifth 0.74 : 1
Sixth 0.64 : 1
Reverse -5.09 : 1

Even better, here's the spec sheet on them: https://www.allisontransmission.com/...rsn=877fbf1c_2

the 2500 camew in 5 speed up until 2006.. from 2006 on it is capable of 6 speed with a 4th or 5th gen TCM and software changes.. no school bus is produced wuith 6th unlocked.. several forum threads are open about the procedures for 6th.. the pre-2006 models were 5 speed only models unless you change the TCM, harness and the valve body... the upgrades arent cheap... the pre 06 models simply had the rotating assembly and clutch pakcs for 6 gears but werent set up to ever utilize them...



-Christopher

[Pizote]

Originally Posted by cadillackid

the 2500 camew in 5 speed up until 2006.. from 2006 on it is capable of 6 speed with a 4th or 5th gen TCM and software changes.. no school bus is produced wuith 6th unlocked.. several forum threads are open about the procedures for 6th.. the pre-2006 models were 5 speed only models unless you change the TCM, harness and the valve body... the upgrades arent cheap... the pre 06 models simply had the rotating assembly and clutch pakcs for 6 gears but werent set up to ever utilize them...

Thanks for the clarification - I knew about the upgrades, just wasn't able to pull it from the recesses of my brain ;)

[Mountain Gnome]

I've got the Allison AT545 in mine. Put her in gear, and she starts crawling at idle, and responds well in nearly all situations, except at the "line" between 2nd and 3rd - coasting at around 22MPH on a slightly bumpy, horizontally flat road with little to no fuel, the tranny "shudders" as it rapidly switches back and forth between 2nd and 3rd; I think this is related to the "bouncy" rear-end as torque is loaded and unloaded into the system in these specific conditions. That said....

I don't use my bus to carry a load of kids, stopping at every street corner, trying to give them a safe, smooth ride. Mine is now a highway vehicle, and I want an overdrive. I was thinking of the Alison AT3020 (I think it was called), but now I realize there is the AT2500 also. Can anyone say anything about the differences, strengths and weaknesses of these units?

I am really thinking of selling my AT545 while it is still in great condition while I can still get some cash out of it, and installing an overdrive unit. After crossing the country with the AT545 at 2500RPM, I think I could get so much better fuel mileage in my 5.9L Cummings (don't they call this motor "the sipper?"). I drove manual tranny vehicles most of my life, and I am always wanting to reach down and upshift to pull the low-end torque out of my motor, but this tranny only understands high-end horsepower, and, as the owner's manual states, is designed to keep the RPM's high for an extended period of time, for city driving.

[Tango]

Good luck selling the 545. I offered my fully operational unit for free and got no takers. Not even as a core. Called a couple of heavy duty tranny shops and they passed on it too. Went as scrap.

[EastCoastCB]

When I upgrade my transmission I'll have a fresh reman 545 up for grabs... I bet I'll end up scrapping it.

[Tango]

There is a trend here. A couple of the big tranny shops I offered it to free said they don't even work on 545's any more (?).

[cadillackid]

Originally Posted by Mountain Gnome

I've got the Allison AT545 in mine. Put her in gear, and she starts crawling at idle, and responds well in nearly all situations, except at the "line" between 2nd and 3rd - coasting at around 22MPH on a slightly bumpy, horizontally flat road with little to no fuel, the tranny "shudders" as it rapidly switches back and forth between 2nd and 3rd; I think this is related to the "bouncy" rear-end as torque is loaded and unloaded into the system in these specific conditions. That said....

I don't use my bus to carry a load of kids, stopping at every street corner, trying to give them a safe, smooth ride. Mine is now a highway vehicle, and I want an overdrive. I was thinking of the Alison AT3020 (I think it was called), but now I realize there is the AT2500 also. Can anyone say anything about the differences, strengths and weaknesses of these units?

I am really thinking of selling my AT545 while it is still in great condition while I can still get some cash out of it, and installing an overdrive unit. After crossing the country with the AT545 at 2500RPM, I think I could get so much better fuel mileage in my 5.9L Cummings (don't they call this motor "the sipper?"). I drove manual tranny vehicles most of my life, and I am always wanting to reach down and upshift to pull the low-end torque out of my motor, but this tranny only understands high-end horsepower, and, as the owner's manual states, is designed to keep the RPM's high for an extended period of time, for city driving.

OK.. so you can buy a fully reman AT545 for aboiut $550 so that doesnt bode well for you selling a somewhat Busted AT545 for much..


yours is doing the 2-step Dance.... thats a sign its getting pretty low line pressure at low RPM... line pressure drops it downshifts.. then the RPM goes up because the 2-3 gradient is enough the engine rpm spikes... that spins thye pump faster and now it upshifts.... slow-down the engine RPM. and it drops pressure again... you get the shudder..



you can put a line pressure gauge on it to be sure.. but its on its way to being a great anchor for someone's Boat...



you want to upgrade? go with a BUILT 1000 or a 2000 series swap... its gonna be some work.. you can read my thread 'RedByrd Transformation' top see what it takes to upgrade from a mechanical transmission to a 6 speed overdrive.. I chose a brand new performance built 1000 for my build.. others have bought a working pull for a 2000 from their engine from a bus. which saves some coin..



going to the 3060. is going to require some mechanical work in extra frame mounts, a new shifter.. plus the electronics.. and the sheer weight of stuffing it up under the bus..



to stay all mechanical you can go 643 which is heavy. and no overdrive but its darn near bulletproof ... on a cummins 5.9 you'll need an extra support for a 643 to go in as well.. as well you may need a new flywheel housing..



for those with a navistar DT-360/408/466(e). just pull the SAE3 ring, swap the flexplate, bolt up a 643 and roll wheels...





can you save your 545? you can drop the pan, swap the filters both internal and external and see if you get lucky.. but most likely you will find lots of metal materials on your pan magnet (and your VSS sender) which usually is the reason the line pressure is next to nothing at idle...



-Christopher

[Mountain Gnome]

Originally Posted by cadillackid

OK.. so you can buy a fully reman AT545 for aboiut $550 so that doesnt bode well for you selling a somewhat Busted AT545 for much..

Hmmm...that is $1000-$2000 less than I thought

Originally Posted by cadillackid

yours is doing the 2-step Dance.... thats a sign its getting pretty low line pressure at low RPM... line pressure drops it downshifts.. then the RPM goes up because the 2-3 gradient is enough the engine rpm spikes... that spins thye pump faster and now it upshifts.... slow-down the engine RPM. and it drops pressure again... you get the shudder..
you can put a line pressure gauge on it to be sure.. but its on its way to being a great anchor for someone's Boat...

RPMs stay the same. The shift happens back and forth so fast (2-3 times per second), the RPMs don't even have time to adjust, and never spike. The torque on the rear-end changes because of the short wheelbase and HandyBus suspension, I believe. No wheel wells mean the wheels don't go "up" at a bump, rather the whole bus does, then it comes bouncing down in front; the whole bus rotates around the rear axle as it does this, changing the torque on the drive wheels as it does this. It only happens on flat ground, no grade, when the road itself is nasty and full of potholes, and the bus starts bouncing in resonance with the road (specifically in Eugene and the way they built their roads in segments, not smooth blacktop, but a few other places, also). It may be related to the Monroe gas-pressurized shocks (the rod extends itself) in the front, and the Gabriel non-pressurized ones in the back (the rod stays where you put it). It really is as bouncy as Tigger the Tiger. I mean really bouncy...just me stepping in it (@115 lbs) makes it bounce twice, and I just put the new shocks in 2 months ago. Should have seen it before!

Originally Posted by cadillackid

you want to upgrade? go with a BUILT 1000 or a 2000 series swap... its gonna be some work.. you can read my thread 'RedByrd Transformation' top see what it takes to upgrade from a mechanical transmission to a 6 speed overdrive.. I chose a brand new performance built 1000 for my build.. others have bought a working pull for a 2000 from their engine from a bus. which saves some coin..

So the AT545 is all mechanical? Wow, I assumed it was electronically controlled. Whatever I put cash into, it will be new, not used, not rebuilt. Unless I break down first. Then it's whatever I can afford.....

Originally Posted by cadillackid

going to the 3060. is going to require some mechanical work in extra frame mounts, a new shifter.. plus the electronics.. and the sheer weight of stuffing it up under the bus..

I knew the new shifter would be needed, and the new computer, and maybe a sensor or two... My owner's manual says the 3060 was one of two options. I just assumed the frame and motor would accept it.

Originally Posted by cadillackid

to stay all mechanical you can go 643 which is heavy. and no overdrive but its darn near bulletproof ... on a cummins 5.9 you'll need an extra support for a 643 to go in as well.. as well you may need a new flywheel housing..

It's overdrive or nothing for me. All mechanical: how about a manual shift? Not too practical in a transit style bus.... But the only Auto-tranny I've ever liked driving was the 3-speed in my 1977 Dodge with a 318 motor. It had a link to the steering, so it knew to downshift in a turn: my biggest complaint about ATs in every other vehicle I've driven. If I thought it was realistic, I would get a 5-speed manual with tall gears and a 2-speed rear-end. I've got a 356 rear-end now....the only way I get to highway speeds...

Originally Posted by cadillackid

can you save your 545? you can drop the pan, swap the filters both internal and external and see if you get lucky.. but most likely you will find lots of metal materials on your pan magnet (and your VSS sender) which usually is the reason the line pressure is next to nothing at idle...

One of the first things I did was drop that pan to look inside! Pan was relatively clean, filters looked ok. Light metallic dust (not like the new Chrysler trannies I've serviced!that's one of the cleaner Chrysler trannies I did, with lots of copper dust in the pan bottom also from worn bushings) and no chunks or flakes of metal. Filled with Valvoline Max-Life Full Synthetic fluid (I swear this is great stuff...avoid the Wally World brands!), then drained and refilled the fluid and changed the spin-on again 3000 miles later at the next motor oil change. Had trouble finding the correct in-pan filter kit. The one NAPA gave me had the right filter, but the grommet did not match the diameter of my pick-up tube, and I had to use the one from the old filter.

Some cat on this sight broke down a few months ago in....Arizona was it....and I remember him ugrading from a AT545 to a 3060, as many of the folks here recommended, but I don't remember his bus or motor. I remember it costing him about $5000 or something, give or take $1000. Even if I got zip for my boat anchor, I would consider doing that. I still think it would pay for itself, as my bus was chosen to be a daily driver, and I like to travel. I'm even thinking of a late-model ( post 2008 ) Cummings from a Dodge Ram truck, as they get far more power...but that's when I'm super rich....

Thanks so much for your input! I still want to be your apprentice. I have my own tools. You gots a lot of the knowin' in ya....
Aloha!

[EastCoastCB]

Originally Posted by cadillackid

OK.. so you can buy a fully reman AT545 for aboiut $550 so that doesnt bode well for you selling a somewhat Busted AT545 for much..


yours is doing the 2-step Dance.... thats a sign its getting pretty low line pressure at low RPM... line pressure drops it downshifts.. then the RPM goes up because the 2-3 gradient is enough the engine rpm spikes... that spins thye pump faster and now it upshifts.... slow-down the engine RPM. and it drops pressure again... you get the shudder..



you can put a line pressure gauge on it to be sure.. but its on its way to being a great anchor for someone's Boat...



you want to upgrade? go with a BUILT 1000 or a 2000 series swap... its gonna be some work.. you can read my thread 'RedByrd Transformation' top see what it takes to upgrade from a mechanical transmission to a 6 speed overdrive.. I chose a brand new performance built 1000 for my build.. others have bought a working pull for a 2000 from their engine from a bus. which saves some coin..



going to the 3060. is going to require some mechanical work in extra frame mounts, a new shifter.. plus the electronics.. and the sheer weight of stuffing it up under the bus..



to stay all mechanical you can go 643 which is heavy. and no overdrive but its darn near bulletproof ... on a cummins 5.9 you'll need an extra support for a 643 to go in as well.. as well you may need a new flywheel housing..



for those with a navistar DT-360/408/466(e). just pull the SAE3 ring, swap the flexplate, bolt up a 643 and roll wheels...





can you save your 545? you can drop the pan, swap the filters both internal and external and see if you get lucky.. but most likely you will find lots of metal materials on your pan magnet (and your VSS sender) which usually is the reason the line pressure is next to nothing at idle...



-Christopher

I don't know that the 643 requires its own mount. IIRC the Bloems didn't have to have one added when they upgraded. But I could very easily be wrong.

[EastCoastCB]

Originally Posted by Mountain Gnome

Hmmm...that is $1000-$2000 less than I thought



RPMs stay the same. The shift happens back and forth so fast (2-3 times per second), the RPMs don't even have time to adjust, and never spike. The torque on the rear-end changes because of the short wheelbase and HandyBus suspension, I believe. No wheel wells mean the wheels don't go "up" at a bump, rather the whole bus does, then it comes bouncing down in front; the whole bus rotates around the rear axle as it does this, changing the torque on the drive wheels as it does this. It only happens on flat ground, no grade, when the road itself is nasty and full of potholes, and the bus starts bouncing in resonance with the road (specifically in Eugene and the way they built their roads in segments, not smooth blacktop, but a few other places, also). It may be related to the Monroe gas-pressurized shocks (the rod extends itself) in the front, and the Gabriel non-pressurized ones in the back (the rod stays where you put it). It really is as bouncy as Tigger the Tiger. I mean really bouncy...just me stepping in it (@115 lbs) makes it bounce twice, and I just put the new shocks in 2 months ago. Should have seen it before!



So the AT545 is all mechanical? Wow, I assumed it was electronically controlled. Whatever I put cash into, it will be new, not used, not rebuilt. Unless I break down first. Then it's whatever I can afford.....



I knew the new shifter would be needed, and the new computer, and maybe a sensor or two... My owner's manual says the 3060 was one of two options. I just assumed the frame and motor would accept it.



It's overdrive or nothing for me. All mechanical: how about a manual shift? Not too practical in a transit style bus.... But the only Auto-tranny I've ever liked driving was the 3-speed in my 1977 Dodge with a 318 motor. It had a link to the steering, so it knew to downshift in a turn: my biggest complaint about ATs in every other vehicle I've driven. If I thought it was realistic, I would get a 5-speed manual with tall gears and a 2-speed rear-end. I've got a 356 rear-end now....the only way I get to highway speeds...



One of the first things I did was drop that pan to look inside! Pan was relatively clean, filters looked ok. Light metallic dust (not like the new Chrysler trannies I've serviced!that's one of the cleaner Chrysler trannies I did, with lots of copper dust in the pan bottom also from worn bushings) and no chunks or flakes of metal. Filled with Valvoline Max-Life Full Synthetic fluid (I swear this is great stuff...avoid the Wally World brands!), then drained and refilled the fluid and changed the spin-on again 3000 miles later at the next motor oil change. Had trouble finding the correct in-pan filter kit. The one NAPA gave me had the right filter, but the grommet did not match the diameter of my pick-up tube, and I had to use the one from the old filter.

Some cat on this sight broke down a few months ago in....Arizona was it....and I remember him ugrading from a AT545 to a 3060, as many of the folks here recommended, but I don't remember his bus or motor. I remember it costing him about $5000 or something, give or take $1000. Even if I got zip for my boat anchor, I would consider doing that. I still think it would pay for itself, as my bus was chosen to be a daily driver, and I like to travel. I'm even thinking of a late-model ( post 2008 ) Cummings from a Dodge Ram truck, as they get far more power...but that's when I'm super rich....

Thanks so much for your input! I still want to be your apprentice. I have my own tools. You gots a lot of the knowin' in ya....
Aloha!

Yeah I'm 99% sure you're talking about the Bloem's bus. It was a 643 they upgraded to, though.

[johnbloem1974]

Yup! Sounds like my experience! AT545 to the MT643 was a technically easy swap! -Unbolt and turn old tranny to boat anchor
-remove adapter ring and spacer and flexplate
-put in new flexplate
-put new cooler line fittings
-bolt on new tranny and reconnect all lines/plugs
-enjoy the hell out of new tranny with lockup!

John

[cadillackid]

Originally Posted by EastCoastCB

I don't know that the 643 requires its own mount. IIRC the Bloems didn't have to have one added when they upgraded. But I could very easily be wrong.

im not sure but i think on the 5.9 the 643 requires an auxilliary mount.. on an international DTA360 / 466 it does NOT.. on a navistar V-8 diesel it DOES..



Bloem has a DT-466E.. I have a DT360.. neither require secondary mounts.. the books even show this..



i'll have to see if I have a book showing the 643 mount up for a 5.9, I dont think i do.. but I remember being told the 8.3 doesnt require the mount but the 5.9 does..



the V-8 diesels SHOW the secondary mount points for the 643.. the allison 1000 / 2000 do NOT require secondary mounts.. they can be built to use the same Bell / offset / converter pattern as a 545.. thats whow i did mine when I swapped the 1000 in.. I did **NOT** use a Duramaxx GMC 1000 (which is what lots of people try to do).. there are mounting kits available to mount a GMC Duramaxx style 1000 to a cummins 5.9


CAC (custom Automatic Conversions in gulf breeze FL) specializes in making and selling these pieces.. when I got my trans dfrom them.. we had suncoast build my trans for SAE3 bell / tail so it would bolt right up where the AT545 came off... drop it down, hoist it up and make the new bits for the slightly different shifter / p0arking brake and speed sensor setups..



on a Fly-by-wire engine like a navistar DT466E / T444E the modulator is electric .. thats the only electric control on the AT545... there are swtiches for neutral safety and reverse lights on the 545 as well..



the 643 is also all mechanical except for the modulator on a fly-by-wire engine


back to your "shudder" how do you even know its the trans without putting a pressure gauge on it to see if it is actually gear changing back N forth? it could be driveline slop.



my red short bus along the freeway bounces lots too.. even with rear air-ride.. the small wheels ride rougher than the large ones.. running the tires at recommended values vs the high-side 100 PSI many use as standard helps with ride quality.. weight the axles, look up the weight / pressure table for your tires and inflate acordingly.. seems to make the bus ride smoother..

-Christopher

[Mountain Gnome]

Originally Posted by cadillackid

back to your "shudder" how do you even know its the trans without putting a pressure gauge on it to see if it is actually gear changing back N forth? it could be driveline slop.

my red short bus along the freeway bounces lots too.. even with rear air-ride.. the small wheels ride rougher than the large ones.. running the tires at recommended values vs the high-side 100 PSI many use as standard helps with ride quality.. weight the axles, look up the weight / pressure table for your tires and inflate acordingly.. seems to make the bus ride smoother..

-Christopher

Driveline shows no sign of slop, driving, or by hand. It only happens at exactly 22MPH, the speed at which, when the road is smooth, it will downshift (smoothly and quietly) as I decelerate from 3rd to 2nd. It happens when I cruise at this speed, either coasting or with the sightest throttle, only on flat, bumpy ground. It is not a resonant vibration, but a hard, banging shudder, as the tranny tries to switch gears back and forth too fast. It is like it can't decide which gear is best.... All other times, the tranny shifts smooth, quietly, and pulls strong with no hesitation.

My bus bounces everywhere. Highways are better than the streets in Eugene, for sure! But drive over a dime, and you know it.

[Tango]

Just a kwik note...


Skoolies are typically way over sprung. They set them up to handle absolute max gross (think 72 overweight 7th graders) and consequently they tend to be very stiff & bouncy at anything less. Lots of folks have either removed a few leaves or re-sprung at a lower rate. I cut the rate on my rear by 50%...but stiffened the front by 350 pounds to compensate for the weight of the little Cummins I stuffed in there. Pretty wise practice to adjust the spring rate to whatever the new loaded weight and distribution might be. And quite a few have opted to add adjustable air bags.


Happy trails.

[EastCoastCB]

Originally Posted by Tango

Just a kwik note...


Skoolies are typically way over sprung. They set them up to handle absolute max gross (think 72 overweight 7th graders) and consequently they tend to be very stiff & bouncy at anything less. Lots of folks have either removed a few leaves or re-sprung at a lower rate. I cut the rate on my rear by 50%...but stiffened the front by 350 pounds to compensate for the weight of the little Cummins I stuffed in there. Pretty wise practice to adjust the spring rate to whatever the new loaded weight and distribution might be. And quite a few have opted to add adjustable air bags.


Happy trails.

As many buses as I've seen with broken leafs I'd have to seriously contemplate removing any.

My 04 shorty is leaf sprung and it rides real nice just the way it came. No bounce!

[jazty]

My 1997 is all leaf sprung. When I first got it the ride was quite bouncy. Changed out the shocks and there was an improvement. The most drastic change, however, was from separating the rear leafs, flap-wheeling them smooth, cleaning them up and re-assembling with HDPE sheets between the leafs. World of a difference!

[Mountain Gnome]

I finally unloaded the 2500lbs of stuff from my bus this weekend, and ready to clean inside, fix leaks, paint, and build up the interior. Yesterday was the first time I drove it unladen with the new shocks. I also did some basic tests.

First I hopped in back, rear of the rear axle, and while standing "let my knees go" so my upper body dropped maybe 2 inches, then stopped. The bus bounced twice. Very little, but noticeable. Again I'm only 115lbs, and that was shock-loading it with only my upper body weight. I moved to the front, and it was a little more noticeable.

Step into the front up the stairway, and the bus noticeably bounces. Not so in the back door. Took it driving, and paid very close attention to the way it bounces. The front springs have no curve, and hitting a bump the wheel does not compress upward much at all, but springs back down with great force, pushing the whole front of the bus up; as the front goes (way) up, it rotates around the rear axle. You can actually hear the torque on the motor/tranny change as this happens.

The rear springs are duel. The upper pack is near strait like the front, with a slight bow downward, while the lower pack bows upward, and they are only half-length in front of the axle (more like a leading arm). Since I ride forward of the front axle, it is hard for me to evaluate the exact condition of bounce in the rear, but the issue seems to be the motor and tranny hanging off the front of the bus, making it bouncier.

I attempted to create the tranny shudder and tried to cruise at 22 mph on what I thought was smooth road, with as little fuel pedal as can be possible - a mouse standing on the pedal. The slightest bounce started the shudder-banging process. I attempted again 1/10 mile later, and the road was smooth, and the shudder-banging did not occur.

One more clue: when I got the bus, both wheels sat the same in their wheel wells. After changing the shocks, I noticed the rear wheel sits deeper in the well than the front; i.e. there is more space above the front wheel than I remember there being with the original (BlueBird branded but completely shot) shocks. As mentioned previous, the Front got new pressurized Monroes, the rear got non-pressurized Gabriels. I drove it from AZ to SF Bay, then to Eugene, and back to the SF Bay. I first noticed the shudder-banging in Eugene that trip. They fluid was smelling burnt, I assumed from the mountain passes N. of LA, and between Shasta and S. Oregon, but it was still red. I changed it when I got my tools shipped and picked them up back in Cali; and was hoping that would solve the problem.

Well, gotta go change the motor oil....Aloha all!

I am wondering if there is a kit that I could add a second shock at each wheel-well, 'cause these shocks seem to be for a pickup truck, not a 25000 GVWR bus. Especially the Gabriels. I could so easily move the strut-rod when mounting them, I had to wonder how they could work at all? I must assume they build resistance as the rod is moved in/out rapidly going over bumps while driving; otherwise, I might as well remove them...
But the mix-and-match sets were all I could find without waiting 2 weeks...and the only two brands that were said to fit.

But then I never had luck with Gabriel or Monroe struts in my mom's Pathfinder over the years, either. Had a client with a Subaru that I had to warranty his Monroe strut in a month. Both were knocking loudly within 10k miles. I kept Ranchos on my 4x4, and they were awesome!, but when I inquired, they said they did not have anything for my bus....

Anyway, it's weird how shocks and springs can relate to trannies, eh?