Newbie with Transmission Concerns

[WBissell]

Hello all. I'm a proud new owner of a well maintained '92 extra-cab, 4x4, auto trans. She has 128K miles which, if I'm understanding these engines, its just broken in. This is my first diesel. I'm writing because I'm concerned with the auto trans. It seems to be shifting fine (mostly but I'll get to that) but the previous owner has upgraded induction/exhaust system with the Banks Stinger-Plus system and a cold air intake. My intent is to tow an RV Trailer weighing no more than about 5000-7000 lbs which, according to the owners manual, is at the limit of this truck. I was a little suprised at this as I'm sure I've seen these trucks towing much more than that! What can I do to maximize the life of this transmission? What upgrades can I do at this mileage or should I just start over with a rebuild or new?



As to the shifting of this trans, I've noticed that when she's not completely up to operating temperature (but close... I've driven about 8 miles), the overdrive doesn't want to upshift unless I let up on the accelerator. It then drops into OD and is fine. However, when at around 50 or slower (which I do take it out of OD below 45 mph) she'll go into OD when I perform the above step but will drop out of OD at the slightest load/incline. Trans works better the warmer it gets. Is this normal? Trans fluid looks and smells normal (slightly sweet) and according to the previous owner, serviced regularly.



I've tried to upload a photo but I can't seem to get the file size small enough. Any suggestions on this? Thanks again.

 

[WJune]

My truck with the 90 ctd and 3spd auto was slow to get into high when cold. Former owner had rebuilt and maintained trans ( he said), but first time I pulled a loaded trailer, it stopped going into 3rd. Pulled pan and found band lining in it, all adjustment used up. Think it was run low on fluid as it leaked at rear seal.

 

[CSchafer]

Not an automatic expert but I think the tps controls overdrive up and down shift. My dads had the same problem and was a pain to drive. The tps had a little adjustment but he ended up slotting the holes to make it think he was giving it more go pedal than he was. worked awsome now he can actually use the torque instead of having down shift and come out of the power band. Hope this helps.

 

[ARhine]

6K lbs is nothing. Don't start worrying about it until you get over 12K.



Search for "TPS" for you shifting troubles.

 

[mudcat]

Put a transmission temp guage on it to keep track of temps. A aux transmission cooler is a good idea too, I also run a double deep transmission pan for more fluid capacity. If it revs and doesn't go anywhere with a load behind it on hills you will greatly benefit from an aftermarket converter. The factory loose converters will create heat very quickly while towing. I tow through the hills of KY, TN and VA with a slide in camper pulling between 4000 and 7000lbs and have no heat issues at all even on the longest hills around here.

 

[WBissell]

Thanks everyone for the info. I will look into the TPS (Throttle Position Sensor, right?) to see if that helps. Good to know about the towing capacity. 6000 just didn't seem right. Thanks again.

 

[BushWakr - RIP]

I've got some detailed info on "how to" for the TPS... . just do some looking... . if you can't find it say the word and I'll see you get a full copy of my text file right away...

You might also want to adjust your throttle valve cable (aka: kickdown cable) back about 1/8".

When you do an oil/filter service use Ford type "F" /dexron mercon type 2 oil.

They have less friction modifiers in them and are a more "aggressive" oil. They usually result in a firmer shift and less slippage which is a good thing for us guys.

If you go to a lower stall TC you really should also have a shift kit put in and the line pressures tweaked up a tad to go with it.

All this will improve the 'hold' as you go thru the gears and limit your slippage which can really generate fluid heat big time.



pb...

 

[1stgen4evr]

"I've noticed that when she's not completely up to operating temperature (but close... I've driven about 8 miles), the overdrive doesn't want to upshift unless I let up on the accelerator. "



The computer blocks OD until the temp comes up. Normal.



James

 

[Greenleaf]

I think the computer will not block OD unless it's like too cold to be driving the turck. I have driven my 92 (a few times) below freezing and it goes to OD right out of the box. The FSM tells us it REALLY COLD but I don't recall what it is exactly.



You need to cleran and / or adjust the tps and connectors.



I can help with the picture resize if you PM me.

 

[WBissell]

Thanks for the info

Thank you all for the wealth of info. REALLY appreciate it. Will be taking the truck to a diesel mechanic to see if there are other issues with the truck just so I know what I need to do. Thanks again.