Questions specific to Cummins 5.9 & Allison 545

[SlowMotion]

Just got my '95 Ford with 5.9 Cummins and Allison 545 AT. The bus has 100k on it all from the school distict. I didn't get any service records. Seems to run and drive great .

If anyone can offer some input on any of the following questions that would be great. This is my first bus, not to mention my first diesel.

~ What is the oil capacity including filter change? Same as a '95 Ram Diesel?

~ What should I do with this Allison 545? Should I change the fluid and filter? Or just filter and top it off?

~ Thinking of adding a tranny temp guage, anyone done this? Do you have to add a sensor or is there one to read off?

~ Also looking to install a tach to monitor trans slipage, I guess this needs to read off the alt? Will any tach work just wired to the alt rather than coil?

~ How do I tell what injector / lift pump I have? Aren't some less desireable, especially for WVO?

I am sure I'll have more for you guys....

[the_experience03]

Originally Posted by SlowMotion

~ What is the oil capacity including filter change? Same as a '95 Ram Diesel?

I'm not sure what the actual capacity is, but I'd be willing to bet it is a whole lot more than a Dodge pickup. My 6.6 Brazilian holds 20 quarts.

Originally Posted by SlowMotion

~ What should I do with this Allison 545? Should I change the fluid and filter? Or just filter and top it off?

I did my filters (there is one in the pan, a spin on, and I actually have an additional inline unit) because my bus was approaching 100,000 miles, a recommended interval for all of them. I think you might want to consider doing the same.

Originally Posted by SlowMotion

~ Thinking of adding a tranny temp guage, anyone done this? Do you have to add a sensor or is there one to read off?

You will most likely have to put a sending unit in for the gauge. It is possible that there is one there somewhere, but chances are not good.

Originally Posted by SlowMotion

~ Also looking to install a tach to monitor trans slipage, I guess this needs to read off the alt? Will any tach work just wired to the alt rather than coil?

Ok. You really have me confused here. There is no pulse signal from an alternator that would work for a tach. Most likely you'd just fry the tach. It also wouldn't be measuring the transmission in any way, shape, or form. Modern electronically controlled transmissions monitor for slip using either hall effect switches or variable reluctors set up on the turbine shaft and output shaft as well as an intermediate shaft speed on the center support in many cases. There is no way to monitor slippage other than that, a series of what are essentially vehicle speed sensors.

Now you can watch in a more roundabout way. Top gear in an AT545 is 1:1. This means that when the torque converter is in coupling phase (not to be confused with lock-up which this transmission doesn't feature) you should see a 1:1 chance in vehicle speed and engine speed. If you see the speedo dropping off and the tach staying put, such as when going up a hill, the torque converter is slipping/multiplying torque just the way it is supposed to.

Why are you interested in watching slip anyway? Torque converter slip is normal. Clutch and band slippage is not. You're going to have a very hard time determining what it's doing other than just by feel on a mechanical transmission.

Originally Posted by SlowMotion

~ How do I tell what injector / lift pump I have? Aren't some less desireable, especially for WVO?

There should be a tag on it that states the model number.

Inline pumps (desirable for WVO due to less moving parts) will have all the lines in a row like this.



Rotary pumps will look a bit like a distributer with all the lines in a circle.

[SlowMotion]

Thanks for the info!

On the tach I am pretty sure I picked up the alt wiring while wondreing through some diesel sites trying to learn some stuff about my motor.

Like this - "I mounted the pick-up on the lower passanger side of the alternator, right below the ride for the bolt hole, on the front side of the alternator. It hasn't missed a beat in three years. " http://www.cumminsforum.com/forum/89-93 ... stall.html

I had heard 4.5 gal for oil but not definatively. If I am gonna need to drop the pan on the trans and replace all the fluid I would like to know how much ATF I need on hand ... and so I can figure total costs. Thanks again.

[Redbear]

If I am gonna need to drop the pan on the trans and replace all the fluid I would like to know how much ATF I need on hand ... a

Most good auto parts stores will give full cash-back credit for everything you return with a receipt if you haven't used it (except perhaps opened electrical parts). When short of money at the end of the month, I've been known to return parts I haven't got around to installing, only to buy them back again two months later.

So, find a good store, buy two or three times as much fluid as you think you'll need, and return the rest after the job. It might not be cheap up front, but it's better than finding out you're short when you have everything apart.

[the_experience03]

Originally Posted by SlowMotion

Thanks for the info!

On the tach I am pretty sure I picked up the alt wiring while wondreing through some diesel sites trying to learn some stuff about my motor.

Like this - "I mounted the pick-up on the lower passanger side of the alternator, right below the ride for the bolt hole, on the front side of the alternator. It hasn't missed a beat in three years. " http://www.cumminsforum.com/forum/89-93 ... stall.html

I had heard 4.5 gal for oil but not definatively. If I am gonna need to drop the pan on the trans and replace all the fluid I would like to know how much ATF I need on hand ... and so I can figure total costs. Thanks again.

Ok, this all makes far more sense to me now. I thought you were actually trying to physically monitor the difference between transmission input and output speeds. I think I've spent too much time working on electronic transmissions in new cars that actually do just this. You're just looking to install a tach to monitor engine speed and therefore watch slip that way which makes FAR more sense to me.

Yes, an alternator mounted pickup will work. So will a Cummins mechanical tach. Heck, you might even be able to find something that uses a VR sensor triggered by the spinning flexplate. Basically you need something ferrous and toothed that will spin at a constant rate relative to the crankshaft. The armature of an alternator certainly fits the bill here. I would just be worried about background noise. I would think that any current draw while the engine was off would cause the tach to do some goofy things. I suppose wiring the tach through the ignition switch so that it will only operate with the key in the "run" position.

I put 5 gallons of oil in my AT545, but I had many filters to fill. Count on buying two cases of Dex/Merc and go from there.

[paul iossi]

alternater tachs are the standard for marine and industrial applications

[the_experience03]

The biggest disadvantage I can see to an alternator tach is the same one I will be dealing with with a speedo in a project. Before you can get it to work you need a working one to set it! I *think* Harbor Freight sells optical tachs though. I'm going to be stuck using a GPS and a pace vehicle. Hopefully I won't be utilizing the nice officer writing me a ticket to get my speedo dialed in...

[paul iossi]

not so, you can just do the math for a speedo, or take your tire diameter and rear axle ratio to the speedo shop and they will do the math for you. speedos are calibrated to trans output shaft or driveshaft rpm, one and the same unlss you run an auxillary over/under drive unit.

60mph = 1mile per minute
1mile =5280 feet
measure the tire circumference in inches and divide by 12 to get feet per rev
5280 divided by tire circumference in feet = tire revs per mile
tire revs per mile times axle ratio = driveline revs per mile,
driveline revs per mile will get you the right gear for the speedo drive.

[SlowMotion]

So I got a chance to mess with the bus today and it does have the inline style bosch pump.

I also started changing the oil and it turns out the drain plug has been killed. I got it off with vice grips but I want to replace it. Orielly's said they didn't have anything that big. It seems to be the same thread as an o2 bung / spark plug. I guess I'll hit up the ford dealer.

Should this be readily available somewhere?

[the_experience03]

Ask for the Dorman/Motormite book at a different parts store since O'Reillys apparently didn't want your business. They might not have it on hand, but any parts store should be able to get it overnight.

[lapeer20m]

do you think it's just National pipe thread? or a standard coarse or fine thread bolt? You can stop by a nut/bolt shop and they'll put a thread guage on it to see what it is. there are a couple of "midwest bolt and screw" stores around here.

[paul iossi]

It's not pipe thread, any dodge dealer or truck shop should have the right drain plug and gasket.

[SlowMotion]

Alright guys, got handled I think. It screws right into an o2 bung so from that I deducted that it was 18 x 1.5 thread. Neither Orielly or AutoZone could get anything over 14mm so I stopped by Bumper to Bumper and they had a non magnetic on hand and ordered me a magnetic one for $5.50 .

Had to order the other fuel filter anyway. Wix 33421 , $5 cheaper than ordering it from Oreilly and AZ couldn't even order it

So under $30 for both. Not bad.

[Elliot Naess]

I have purchased a tach from a commercial speedometer shop. This uses a sensor on the flywheel. My tranny already has the threaded hole for it near top left of bell housing -- plugged from the factory with a red plastic plug. Tach is Isspro R8530M -- $117.57. Sensor is CS4-106 -- $25.

Not installed yet.

[SlowMotion]

Yeah, since I have been searching I have seen that isspro mentioned a few times on the cummins forums.

Here's another question. I noticed where the wiring harness comes to the alternator there is an extra plug hanging down by the alt. Whats that for?

Also, it seems to hold right at 4 gal of oil.

[zim]

A little late, but I'll put it here so the next guy can find it... the VT255 (Cummings 5.9l) in my '82 Thomas took 5.5 gallons with a filter change. The filter was on the shelf at the local o'reilly's and I found a good price on the Rotella 15w40

[nevrenufhp]

I thought the VT255 was the "trippple nickel", Cummins V8(555 ci).

[zim]

Originally Posted by nevrenufhp

I thought the VT255 was the "trippple nickel", Cummins V8(555 ci).

Me and my dyslexia... my bus has a VT225