Archived Transmission/Torque converter failing

[Great Oak]

Issue: Transmission sputtering at 55 to 60 mph. Torque converter locking and unlocking while driving. weird part when depressing throttle to floor engine did not rev up this was while moving on highway. When I moved transmission to neutral while rolling and depressed throttle to floor the engine would rev up .

About three years ago I replaced the two little adjust bits that that secure second gear and first gears. I knew I was on borrowed time so to make it three years is pretty good.

Just limped home at 15 mph. seems like I only have 1st or 2nd gear. Once home, praise the Lord, I checked transmission dipstick, fluid fine, no burn smell.

I do not have a code check device available.

Does this issue seem like a sensor or electronic issue given that when transmission is in gear and when I press throttle to floor it does not rev beyond the rpm's its currently at. where should I check first?

Please advise.

Preparing to order a Suncoast torque converter and trans rebuild kit.

any help is appreciated.

 

[Great Oak]

update. I think it might be the trans sensor. kinda cold here in south today. I let truck sit for a while to get cold upon starting it and driving it no problems shifted fine.

Looks like it might be the trans temp sensor

 

[cerberusiam]

If your engine did not rev I would look at fuel being the issue. The fuel here in the south is definitely not winterized and LSD's tendency to gell at about 20 degrees makes it suspect if you could not accelerate on the hiway. The jerking might have been the engine running out of fuel.

 

[Great Oak]

Thanks for the reply. It could be the fuel but it seemed more the transmission especially the torque converter. The engine throttle would not rev when it was in gear. for example when the transmission wasn't catching I jammed the pedal to the floor and no engine throttle;e response yet while still moving forward I put truck in neutral and depressed throttle pedal the engine rev
d up[ normal.

not sure why that would occur like it did.


I recall seeing a few years ago certain aftermarket transmission companies would sell a complete rebuild trans in a trans housing and you would send back your old trans- core once new one was in truck. Is that an easier way to go versus rebuilding the trans with a rebuild kit?

 

[cerberusiam]

Unless you have 15k on the back I cannot see these trucks NOT accelerating when you stomp on them at hiway speeds. That is completely indicative of a fuel problem not a trans problem. At the least iyt should have downshifted which may mean you have a dead pedal and an APPS problem.

Have you checked for codes? What year and specs on the truck?

Yes, there are places you can buy a complete transmission and swap it around. Freight is a killer these days, can be well over $1k just to ship one way. You have to be very careful dealing with a remote vendor as warranty gets to be a problem when you cannot take it to them.

Best bet is a builder near you so you ahve a place to complain and face to talk to if there are problems. Where are you located?

 

[Great Oak]

truck is 2001 2500 automatic. Totally stock no upgrades or mods. still have original injection pump. 103,000 miles

The best way to describe what happened is that it started occurring at 55 mph and fluttered between having torque and not having any torque until I could only drive at 15 mph and any additional throttle did nothing to move it faster or to try to get it to shift.

fyi- a couple years ago has to replace the drive band tensioners- those two cheap pot metal type OEM pieces that you adjust for 2nd gear bands. even with the two pieces replaced and adjusted it still hesitates to shift between 1st and 2nd. Other than that it was driving fine for a stock trans and no upgrades.

Primary use of truck is for hauling and I would like to have a bit better towing response versus stock. When I rebuild I just want better towing/torque performance and reliability/longevity.
leaning towards the suncoast rebuild kit and torque converter. anything else recommended without braking the bank? Only performance mod I might add would be a smarty or something to provide a little bit more mph when towing

 

[cerberusiam]

I think you have some fuel or APPS issues going on there. You need to check for codes and see what is there.

A good TC will make a differnce in throttle response as will injectors and a Smarty. Lots of things oyu can do t improve things thne you will need anew turbo to fully utilize them.

 

[JR]

Sounds a lot like an APPS going bad. If you have a check engine light, get the codes pulled up and post them up here.

 

[SnoKing]

2001, turn the key on and off three times leaving it on the third time and write down the codes that cycle on the odometer display! SNOKING

 

[Great Oak]

thank you for the advice. The check engine light is not illuminated.

I will do the code check and advise.

have a great day everyone.

 

[Great Oak]

I checked the codes and there is a 0720 code- output speed sensor

This explains why my truck max'd out at 15 mph on the way home.

Looks fairly straightforward to replace.

any suggestions on why this item may be bad? I replaced this about 4 years ago when I repaired the 2nd gear components and replaced filter.

 

[Great Oak]

I almost forgot. Is there only 1 output speed sensor or are there two? seeing different parts offered online.

 

[cerberusiam]

Neither the trans output shaft speed sensor nor the wheel speed sensor will derate the engine like that. The engine controls are totally separate from the drive train components. Even will both sensors diconnected the engine will rev right to red line and stay there driving.

If the problems have disappeared my guess is you had some fuel gelling in the filter. If you still have issues chnage the filter and check your LP output. You may have to get a scanner capable of reading the PCM to find all the pertinent codes.

 

[Great Oak]

Thanks cerebresium.
how do I clear the error code?

I am going to stop by my normal repair shop- former Chrysler dealer and have them put a scanner on it. will advise.

Just took the truck for a test drive- had it get to normal operating temps and drove it 55mph and above. No torque issues seems like that may have got it. and it could be a fuel issue as well. I tried some new fuel additive and may dump a can of sea foam into the system to see if that offers any improvements.

Thanks for all the help1 It is much appreciated.

 

[cerberusiam]

I would not use Sea Foam. It is only really effective as a cleaner in the filter housing. Heavy dose of Power Service in the grey bottle and some 2 stroke oil for lube would be my choice.

IMO, this little cold snap just exposed how bad the fuel really is in the southern states.

 

[Great Oak]

How much 2 stoke oil should I add per tank?
I have used the power service before with no issues.

recently I bought some Lucas diesel fuel additive. Maybe that loosened some gunk up.

 

[cerberusiam]

I would use a quart of 2 stroke and a quart of PS in a full tank intitially if you suspect fuel issues.