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03-04-2021, 10:43 AM
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#41
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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Quote:
Originally Posted by Doktari
Good to know a small lift is safe. I’d like to lift my Isuzu NPR Motorhome a couple of inches. Can I simply use blocks and longer U bolts? What I like about my skoolie is it’s high enough to crawl under and tinker with it or inspect it without jacking it up. The skirting on the Motorhome makes that harder.
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Blocks are usually not the safest way to go. They send "rotating" forces to the leave springs in a way they are not calculated to endure.
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03-04-2021, 10:48 AM
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#42
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Bus Crazy
Join Date: Nov 2014
Location: NM USA KD6WJG
Posts: 1,515
Year: 1991
Coachwork: Bluebird
Chassis: All American RE 40 FEET
Engine: Cummins 8.3
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Quote:
Originally Posted by ABBus
Blocks are usually not the safest way to go. They send "rotating" forces to the leave springs in a way they are not calculated to endure.
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Yes you are correct. It will show up during hard braking and can cause wheel hop when you need it the least.
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03-04-2021, 12:28 PM
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#43
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Bus Crazy
Join Date: Oct 2017
Posts: 1,222
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
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Quote:
Originally Posted by Doktari
Good to know a small lift is safe. I’d like to lift my Isuzu NPR Motorhome a couple of inches. Can I simply use blocks and longer U bolts? What I like about my skoolie is it’s high enough to crawl under and tinker with it or inspect it without jacking it up. The skirting on the Motorhome makes that harder.
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Generally, yes.
But a "couple" of inches could make a big difference on the U-joint angles for the rear drive shaft (a.k.a. propeller shaft), if the shaft is short from the tranny to the rear axle housing, or if there is a carrier bearing (or two) in the middle of the shaft.
a) for the rear axle, you would want to cut off the mounting "pads" welded on the axle-housing-tube, rotate the axle housing so the pinion flange lines up with the driveshaft, then re-weld on new mounting pads at the right angle.
b) for the carrier bearing, you may or may not want to create a block to drop it down a bit so the whole shaft is strait, and then the angle on the u-joints will be less. This block must "angle" the carrier a bit to match the new driveshaft angle.
c) the u-joint at the rear of the tranny, which will then handle all of the angular offset, will be the one to watch for "premature" wear and tear.
Harbor Freight has a "3 in 1" service set that can remove and press in new u-joints without (usually) having to remove the whole shaft. It looks like a big heavy duty "C" clamp with a screw-drive clamp. If you did that lift, I would suggest always having a new u-joint and that tool with you when traveling, and keep an eye (and ear, and vibrational sense in your skin and belly)
The tool does king-pins and press in ball joints, also. It failed me once, when the guy drove his Toyota 4×4 till the u-joint was nothing but nubs! There wasn't enough left to "push" the caps though and out, and I had to remove the whole shaft and take it to the machine shop. He was not happy. Dumb-*** should not have ignored maintenance!
This link says "ball joints" but it will do u-joints also:
https://www.harborfreight.com/automo...les-63279.html
Small lift safe?
My 1984 Nissan King Cab 4×4 pickup was the baja champ every year that model (720D) was made. I loved hauling *** on dirt and gravel roads, racing my friends in their 4×4s, and usually left them eating dust, way back there. Then I lifted it 1", using bigger rear shackles, and aftermarket torsion bars that I could jack up. That little bit made it want to roll so much, my racing days of sliding sidewards through turns was over.
The only guy who could beat me was in a 1973 Honda Civic, with a 1978 Accord 1.8L (up from the 1.2L) motor, Accord struts in the rear (with springs cut to fit) that jacked it up 3", and Accord lower control arms which stuck out 1" wider with the optional Accord wider rims. That little car was fast on road (beat 5.0L Mustangs at the light and in turns) and offroad!
Be careful with your lifted vehicles. The geometry of the center of gravity can be tight!
__________________
Look at the Sky; look at the River. Isn't it Good?
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03-04-2021, 04:22 PM
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#44
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Bus Nut
Join Date: Dec 2018
Location: Mt Vernon, WA
Posts: 523
Year: 1996
Coachwork: Bluebird, Collins
Chassis: G30 Bluebird Microbird, E350 Shuttle Bus
Engine: 1995 Chevrolet 350, 1992 Ford 460
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Thanks for the suggestions. There’s a lot to consider before changing the suspension and doing a lift. I’ll look at the expeditionportal.com forum also for Isuzu NPR ideas. Ol Trunts skoolie is on a NPR chassis and he removed some leafs from the rear to lower it 1.5”. Lifting is a different set of challenges.
One thing is strange: speaking of U joints, my NPR owners manual says to lube the driveshaft U joints at every oil change. Ive never seen that before and I’d be surprised if anyone does it. This chassis has 70K miles and I don’t know if they have ever been lubed.
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03-04-2021, 11:02 PM
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#45
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Bus Crazy
Join Date: Oct 2017
Posts: 1,222
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
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Quote:
Originally Posted by Doktari
One thing is strange: speaking of U joints, my NPR owners manual says to lube the driveshaft U joints at every oil change. Ive never seen that before and I’d be surprised if anyone does it. This chassis has 70K miles and I don’t know if they have ever been lubed.
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Yea, I'm a bit slack on the "every oil change" schedule, but I do lube them sometimes if they have grease nipples. some cheapo creapo ones don't.
Not just your NPR. Every U-joint in every vehicle. Salty, dusty roads need it more often.
__________________
Look at the Sky; look at the River. Isn't it Good?
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03-05-2021, 09:27 AM
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#46
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Bus Nut
Join Date: Dec 2018
Location: Mt Vernon, WA
Posts: 523
Year: 1996
Coachwork: Bluebird, Collins
Chassis: G30 Bluebird Microbird, E350 Shuttle Bus
Engine: 1995 Chevrolet 350, 1992 Ford 460
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Lubing the U joints every 30,000 miles or so I could understand and handle. But every 3000-4000 (every oil change) miles seems ridiculous. It made me wonder if there is some defect in the design of this NPR. Ive lubed a few of mine before. It was difficult to get the grease gun onto the zerk without rotating the driveshaft. It’s a job for a hoist ideally. And few have hoists. Having said that tpU joints are amazingly reliable for the punishment they take. In 44 years I’ve only had to replace one U joint. So I’m thinking most people just ignore it and I’m certain jiffy Lube quick stop places do lol. Sorry for hijacking the thread. But I got on this topic because I read that changing the front end height even slightly can alter driveshaft angle which can increase the need for lubrication. So it’s not completely off topic from what the OP was asking. Thanks
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03-05-2021, 11:55 AM
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#47
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Bus Geek
Join Date: May 2014
Location: West Ohio
Posts: 3,835
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Quote:
Originally Posted by Jolly Roger bus 223
please somebody send another picture of a spring pack that is not coupled together?
the weight is only on one spring in his pic when both springs should be shouldering the weight.
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The weight is on both springs. The gap you see is just how it was designed. It's supposed to be there.
It looks goofy with the gap because most leaf packs will have a master leaf that attaches to the hanger and shackle with the other leaves applying there force to that master leaf.
In a front suspension leaf pack, they like to have at least 2 master leaves per side in case of breakage. Both leaves will have a loop around the front hanger bolt, and both will be full length and apply pressure at the shackle. If they didn't do this, and the master leaf broke at the eyelet, the axle could easily slide fore and aft, and the driver would lose control.
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03-05-2021, 04:38 PM
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#48
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Bus Nut
Join Date: Dec 2018
Location: Mt Vernon, WA
Posts: 523
Year: 1996
Coachwork: Bluebird, Collins
Chassis: G30 Bluebird Microbird, E350 Shuttle Bus
Engine: 1995 Chevrolet 350, 1992 Ford 460
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It’s a good idea to check the bump stops. Or possibly damage springs, exhaust, etc. Mine were missing completely. They disintegrated and fell out and the exhaust pipe was crushed . So I bought Timbren bump stops and it made a big difference. They also leveled the rear. If my trailer had bump stops the spring may not have broken when it hit a deep pothole.
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03-07-2021, 03:40 PM
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#49
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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I "bet" the best size would have been 9 inches diameter air springs. But there is no room for this size, because of the shocks and air tanks. So, I ordered 4x 6 inch air springs. Dual 6 inches air springs are roughly the same area as a 9 inches air spring. I'll update this post once everything is set up.
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03-07-2021, 04:03 PM
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#50
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Traveling
Join Date: Sep 2013
Location: Virginia
Posts: 2,302
Year: None
Coachwork: None
Chassis: None
Engine: None
Rated Cap: None
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Short answer - it's going to ride high in the rear until the rear suspension has moderate to max load on it. Read on to find out why.
As buses are built to carry a certain amount of weight from the factory, and they are built on what are otherwise incomplete truck chassis, it is very common for such chassis to ride high in the rear when unloaded. This is to allow tire clearance at max load. Even with air suspension, you will see a drop when fully loaded. I used to drive 18-wheelers (many have air ride these days, all of mine did) and the trailer was always taller before loading than after. This is because 46k of freight tends to compress the air bags a little even at max PSI.
A shuttle bus certainly isn't designed to carry 46k, so its scaled-down version is bound to ride low when loaded, like any other. If you want an example, watch the remake of The Italian Job and pay close attention to the scene with the armored car trucks - 1:21 -- 1:23 (the full caper unfolds to 1:30), it will give you an idea of the difference in suspension height when loaded vs unloaded.
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03-07-2021, 06:28 PM
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#51
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Bus Crazy
Join Date: Nov 2014
Location: NM USA KD6WJG
Posts: 1,515
Year: 1991
Coachwork: Bluebird
Chassis: All American RE 40 FEET
Engine: Cummins 8.3
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ABBus, So what is your plan? 2 bags in line 1 in front of the axle and 1 in the rear?
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03-07-2021, 09:01 PM
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#52
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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Quote:
Originally Posted by CHEESE_WAGON
Short answer - it's going to ride high in the rear until the rear suspension has moderate to max load on it. Read on to find out why.
As buses are built to carry a certain amount of weight from the factory, and they are built on what are otherwise incomplete truck chassis, it is very common for such chassis to ride high in the rear when unloaded. This is to allow tire clearance at max load. Even with air suspension, you will see a drop when fully loaded. I used to drive 18-wheelers (many have air ride these days, all of mine did) and the trailer was always taller before loading than after. This is because 46k of freight tends to compress the air bags a little even at max PSI.
A shuttle bus certainly isn't designed to carry 46k, so its scaled-down version is bound to ride low when loaded, like any other. If you want an example, watch the remake of The Italian Job and pay close attention to the scene with the armored car trucks - 1:21 -- 1:23 (the full caper unfolds to 1:30), it will give you an idea of the difference in suspension height when loaded vs unloaded.
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The rear will keep the same height, loaded or unloaded. Air suspension with a mechanical "sensor".
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03-07-2021, 09:03 PM
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#53
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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Quote:
Originally Posted by s2mikon
ABBus, So what is your plan? 2 bags in line 1 in front of the axle and 1 in the rear?
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Yep. The bags will be close to each other, maybe two inches.
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03-07-2021, 09:18 PM
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#54
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Bus Nut
Join Date: Aug 2019
Location: Auburn, WA
Posts: 785
Year: 2000
Coachwork: IC / Amtran
Chassis: 3000 / 33' Flat Nose
Engine: IC T444E / Allison MT643
Rated Cap: 72 Kids / 48 Adults
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Quote:
Originally Posted by Jolly Roger bus 223
it looks like you are missing the clips that hold the spring packs togetherand the single bottom spring is shouldering the weight.
and i dont recall seeing just two springs in a pack so that might be able to be improved upon.
look into the clips to hold the two springs together and see how that looks and feels to you
just adding helper springs will stiffen the suspension but then it gets into how stiff do you really want the suspension on the front.
that botttom spring right now is holding all the weight without the help of the top spring.
either way those springs look tired to me.
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I agree with Jolly. The lower leaf looks almost flat. The springs are supposed to be tied together with each one giving the other support. As a unit, the middle of the leaf set is stiff, yet as you move outwards you find less leafs and long lengths, this gives more cushion.
Without the leaf set being bound together, they can't act as a unit to provide you with steadiness (stiff) and comfort (cushion).
Before adding something to simply raise the bus level, I'd be more focused on solving a potential safety problem (it is your front end after all), which could likely solve your leveling concern and provide a much better ride and handling.
Maybe a local truck repair place could give you some input, again, more for safety than anything.
Best of luck!
__________________
Steve
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03-07-2021, 09:25 PM
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#55
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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Quote:
Originally Posted by Simplicity
I agree with Jolly. The lower leaf looks almost flat. The springs are supposed to be tied together with each one giving the other support. As a unit, the middle of the leaf set is stiff, yet as you move outwards you find less leafs and long lengths, this gives more cushion.
Without the leaf set being bound together, they can't act as a unit to provide you with steadiness (stiff) and comfort (cushion).
Before adding something to simply raise the bus level, I'd be more focused on solving a potential safety problem (it is your front end after all), which could likely solve your leveling concern and provide a much better ride and handling.
Maybe a local truck repair place could give you some input, again, more for safety than anything.
Best of luck!
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There is no problem with the front leaves. They are meant to be this way, it is not a "pack" but two indépendant main leaves.
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03-07-2021, 09:31 PM
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#56
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Traveling
Join Date: Sep 2013
Location: Virginia
Posts: 2,302
Year: None
Coachwork: None
Chassis: None
Engine: None
Rated Cap: None
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Quote:
Originally Posted by CHEESE_WAGON
Short answer - it's going to ride high in the rear until the rear suspension has moderate to max load on it.
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Quote:
Originally Posted by ABBus
The rear will keep the same height, loaded or unloaded. Air suspension with a mechanical "sensor".
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Agree to disagree. I've noticed differences in ride height loaded / unloaded with a few vehicles.
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03-07-2021, 09:33 PM
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#57
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Bus Crazy
Join Date: Oct 2017
Posts: 1,222
Year: 1999
Coachwork: BlueBird
Chassis: TC1000 HandyBus
Engine: 5.9L 24V-L6 Cummins ISB
Rated Cap: 26 foot
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My front springs are not clipped together either.
The rears have a pack of like 10, from short to long, and only the top 2 (long ones) are clipped together. The rear also has 2 inverted long leaves below that big pack, and these are not clipped.
__________________
Look at the Sky; look at the River. Isn't it Good?
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03-07-2021, 09:41 PM
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#58
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Bus Nut
Join Date: Aug 2019
Location: Auburn, WA
Posts: 785
Year: 2000
Coachwork: IC / Amtran
Chassis: 3000 / 33' Flat Nose
Engine: IC T444E / Allison MT643
Rated Cap: 72 Kids / 48 Adults
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Quote:
Originally Posted by ABBus
There is no problem with the front leaves. They are meant to be this way, it is not a "pack" but two indépendant main leaves.
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Yeah, I messed up and only saw the first page of posts.
What I like about the air bags is the ability to adjust them for the comfort and stability of what you drive and how you drive.
Sounds like you have a good plan.
Best of luck!
__________________
Steve
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03-07-2021, 09:45 PM
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#59
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Bus Nut
Join Date: Jan 2021
Location: On the road
Posts: 348
Year: 2013
Chassis: IC RE
Engine: HT570 / 3500SP
Rated Cap: 4
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Quote:
Originally Posted by CHEESE_WAGON
Agree to disagree. I've noticed differences in ride height loaded / unloaded with a few vehicles.
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I guess not all buses are the same 
Mine keeps its height whatever the load on it.
The mechanical link opens a "dump valve" when too high, and a "feed valve" when too low. The margin is very narrow, maybe half an inch. It was funny to look at it return to its set height when removing then engine and then putting it back in. The point is, with or without the engine-tranny combo (around 2400 lbs), same height.
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03-07-2021, 10:15 PM
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#60
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Bus Nut
Join Date: Feb 2019
Location: Communist State of New Jersey
Posts: 964
Year: 2004
Coachwork: IC
Chassis: CE200
Engine: T444e
Rated Cap: 27,500
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Quote:
Originally Posted by ABBus
Frame to ground, front: 25 inches.
Frame to ground, back: 28.5 inches.
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Do you know that's NOT the correct ride height per the manufacturer?
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