Dodge Cummins Diesel Forum banner
1 - 20 of 20 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter · #1 ·
Hi to all.

My 93 truck, traveling at 55mph sometimes has a transmission slip for a few seconds. I has done this twice in 2 months. This is the only trouble I have noticed. The oil is clean, not to old. I have never serviced the transmission in 5 years of owning the truck, and it has 225,000 mi. except for oil/filter change a year ago. I buy the transmission oil at the dealer.

Any advice is appreciated.
 

·
Registered
Joined
·
22 Posts
Discussion Starter · #3 ·
Not 100% sure because it only lasts a couple seconds.

Could it be the variable speed sensor? I changed it about 2 years ago, I installed a napa brand because the dealer was out of stock.
 

·
Registered
Joined
·
7,185 Posts
That above is a TPS delete kit . you plug it in too the wiring and you adjust it to where yo want trans to go into OD . Very easy plug n play .
 
  • Like
Reactions: RHJ

·
Registered
Joined
·
22 Posts
Discussion Starter · #9 ·
Thanks for explanation about TPS.
The truck seems shifts ok. Except for the 2 times it went out of od for a couple of seconds. That is what I think happened.

Can it be the VPS thats about to fail?
 

·
Premium Member
Joined
·
2,170 Posts
VPS?

You mean the TPS?

They fail. THey are servicable but YOU have to cut it apart manually.They are not MADE to be servicable.

if you choose to delet the thing my suggestion is to take that topic elsewhere. Not here. It is almost as bad as a delete smoke limiter topic. Lots of bad things happen. the younger generation do not approve of deleting items from these trucks. Saying no more.
 

·
Steak N' Eggs
Joined
·
398 Posts
any trouble codes?

I meant to say that maybe the variable speed sensor is about to fail. The last variable speed sensor I instaled was not OEM.
Hi I imagine you've checked for any trouble codes but if not you might get a clue there. Sorry if this is stuff you already know but to get the codes do this: turn ign on/off, on/off, on and leave on. Then count the flashes of the 'check engine' light. The flashes form 2 digit numbers and if you miss them the 1st time around you can re-do the ign on/off thing and try again. The number 55 is usually the final set to indicate 'no more codes and finished'. If you don't already have the code translation list here is a link:
'92 and '93 Trouble codes - Dodge Diesel - Diesel Truck Resource Forums
Hope this helps, best regards, TK
 

·
Registered
Joined
·
25 Posts
The problem with the tps sensors is that the carbon track that the wiper rides on is paper thin and it wears through to the brass underneath. This wear usually happens right at highway speed. The reason for the erratic shifting is when the wiper jumps from the carbon track to the bare brass making the computer think that you are giving it full throttle and it sends a signal to the transmission to kick down.

So it will switch between 3 and 4th till you either apply more or less throttle to get past the worn spot.

Here's a photo of inside a tps sensor, the black portion on the upper right is the carbon track. You can see the two wipers on the lower right part that ride on the track. and if my photo was a bit better you would see the exposed brass on parts of the track from wear.



Finally to fix it, I replaced the entire sensor with one from 3.0l caravan it required a bit of modification but if it ever fails again I can get a replacement for $25-30 instead of $250-300.
 

·
Registered
Joined
·
284 Posts
The problem with the tps sensors is that the carbon track that the wiper rides on is paper thin and it wears through to the brass underneath. This wear usually happens right at highway speed. The reason for the erratic shifting is when the wiper jumps from the carbon track to the bare brass making the computer think that you are giving it full throttle and it sends a signal to the transmission to kick down.

So it will switch between 3 and 4th till you either apply more or less throttle to get past the worn spot.

Here's a photo of inside a tps sensor, the black portion on the upper right is the carbon track. You can see the two wipers on the lower right part that ride on the track. and if my photo was a bit better you would see the exposed brass on parts of the track from wear.



Finally to fix it, I replaced the entire sensor with one from 3.0l caravan it required a bit of modification but if it ever fails again I can get a replacement for $25-30 instead of $250-300.
Could you tell us more about the modifications required for the caravan part?
 

·
Steak N' Eggs
Joined
·
398 Posts
  • Like
Reactions: RHJ

·
Registered
Joined
·
25 Posts
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top