94 E420 transmission problem after diff swap. - PeachParts Mercedes-Benz Forum

blueboxgeek09 · #1 10-08-2008, 06:05 PM

1994 e420

So i fell into my desires and swapped out the 2.24 differential for a 2.82 from an s-class.

Took it for a spin and ....DAMN...much quicker....then...

This morning after driving for about 25 miles, the transmission starts shifting funny, the ABS light turns on and then the tranny does not shift from 2-3 or even 3-4 (even at really low throttle).

is it the differential? (the speedometer is off with the actual speed of the car, I have to find something to adjust..suggestions?...I am thinking this is why the ABS light is on)

It shifts fine when cold or if driving short distances.

The transmission was working fine before the swap.

I used 80w-90 gear oil in the diff.

Any suggestions and help are dearly appreciated.

Thanks in advance.

deanyel · #2 10-08-2008, 09:42 PM

What fault codes on pin 6? No ASR on the car I presume.

whipplem104 · #3 10-08-2008, 10:36 PM

The transmission does not care about the diff swap. Try filter and fluid first then check the gov. The shift are not electronically controlled. The only thing to check easy is that the governor gear is not broken. To check the gov. remove the side housing cover on rear driver's side of trans. Push in, remove snap ring and pull the cover off and then see if the gov. can be moved independent of the drive shaft. If so remove the rear cover off the transmission and repl. the gear if broken or the some gov. have a plastic gear that breaks and is repl.

mbdoc · #4 10-09-2008, 08:05 AM

AS posted!
The trans problem isn't related to the diff swap!

Most likely the ABS problem is. A scanner (not ODB2) would reveal codes for that light being on.

blueboxgeek09 · #5 10-09-2008, 11:23 AM

Quote:

Originally Posted by whipplem104

The transmission does not care about the diff swap. Try filter and fluid first then check the gov. The shift are not electronically controlled. The only thing to check easy is that the governor gear is not broken. To check the gov. remove the side housing cover on rear driver's side of trans. Push in, remove snap ring and pull the cover off and then see if the gov. can be moved independent of the drive shaft. If so remove the rear cover off the transmission and repl. the gear if broken or the some gov. have a plastic gear that breaks and is repl.

Thank you, I will check that first thing saturday.

How would I run diagnostic on the ABS?

My car does not have ASR.

Thanks again.

whipplem104 · #6 10-09-2008, 11:42 AM

The abs is pretty easy to diagnose without codes. First if the light comes on after you start moving it is a wheel speed sensor. If it does not come on until after you are reaching higher speeds and I assume this is your problem, that is the diff swap. It will definitely cause the abs light. As far as fixing both the abs and the speedo due to the diff swap, the only way would be to repl. the speedo and abs module with ones calibrated for the rear end ratio. A car that came with this ratio stock. The speedo could possible be done with some aftermarket speedo driver. Something that could be calibrated. This could possibly work for the abs also, not sure.
They both use different sensors. The abs uses the one in the diff and the speedo uses the one in the transmission.

blueboxgeek09 · #7 10-09-2008, 01:37 PM

Quote:

Originally Posted by whipplem104

The abs is pretty easy to diagnose without codes. First if the light comes on after you start moving it is a wheel speed sensor. If it does not come on until after you are reaching higher speeds and I assume this is your problem, that is the diff swap. It will definitely cause the abs light. As far as fixing both the abs and the speedo due to the diff swap, the only way would be to repl. the speedo and abs module with ones calibrated for the rear end ratio. A car that came with this ratio stock. The speedo could possible be done with some aftermarket speedo driver. Something that could be calibrated. This could possibly work for the abs also, not sure.
They both use different sensors. The abs uses the one in the diff and the speedo uses the one in the transmission.

Now it comes on at about 15-20 mph. Before it was coming on at about 50-60 mph.

So is it the wheel speed sensor on the wheels?

Thanks again.

whipplem104 · #8 10-09-2008, 05:45 PM

I assume you mean that it was coming on a 60-80 before the diff swap. In any case this is related to the difference in wheel speed. I had tires that were bigger in the rear on my car once and at 60-80 after prolonged periods the abs light would come on. This will also cause limp ore cruise failure on cars with asr. In your case I think your problem is mostly your diff. Again the only answer I know of would be to repl the abs module with one that had that diff ratio.

Arthur Dalton · #9 10-09-2008, 05:50 PM

WSS sensors on ASR systems are on all 4 wheels and they are computer compared with the additional input of the VSS sensor at the speedo head.
So, all inputs are effected by both different rear diff ratio and tire sizing/pressure.

blueboxgeek09 · #10 10-09-2008, 06:34 PM

Quote:

Originally Posted by whipplem104

I assume you mean that it was coming on a 60-80 before the diff swap. In any case this is related to the difference in wheel speed. I had tires that were bigger in the rear on my car once and at 60-80 after prolonged periods the abs light would come on. This will also cause limp ore cruise failure on cars with asr. In your case I think your problem is mostly your diff. Again the only answer I know of would be to repl the abs module with one that had that diff ratio.

by the module do you mean the entire module under the hood? or is this something else?

Someone else mentioned the neutral safety switch could be a problem for the transmission shifting...?...maybe?

I asked the dealer over the phone and they mentioned the front transmission pump is going bad (hence the bad shifting after the tranny is warm)...again...not sure?

eh..its time for me to get under the car...again...sniff...

deanyel · #11 10-09-2008, 06:48 PM

You really should read the codes on pin 6 - very easy to do. Everyone who owns one of these cars should learn how to read the fault codes. Do a search, lots of info, such as this thread - http://www.peachparts.com/shopforum/showthread.php?t=107630

You don't really have to have ABS on your car. Pull the module in the black box in the engine compartment, pull the warning light in dash and it will soon be a distant memory. You can bring it back whenver you're ready to tackle it.

PS - part number on the ABS control module should be 013 545 94 32.

Arthur Dalton · #12 10-09-2008, 08:03 PM

If one wants to disable either abs or asr for testing purposes, all you have to do is unplug a wss under the hood.

blueboxgeek09 · #13 10-09-2008, 10:20 PM

Quote:

Originally Posted by Arthur Dalton

If one wants to disable either abs or asr for testing purposes, all you have to do is unplug a wss under the hood.

sorry to sound ignorant...what is a wss?..and where is it located under the hood...thanks again guys

Arthur Dalton · #14 10-09-2008, 11:14 PM

Wheel Speed Sensor..just follow the cable up from the sensors..at the end will be the connector plug..........