Ladies and Gentlemen,

My transmission failed on me again last night, truck won't move (I still seem to have reverse). Was cruising down the road at 85km/h and Trans Failure came up with a P0720 (OSS sensor Cct.) and P0722 (output shaft speed sensor no signal) codes. The first time I only got a P0721 code.

This is the second time in 6 months. Last time I spend 3200 to get it rebuilt locally. i don't do any towing, I don't spin my tires etc. and I haven't taken it off pavement since it was rebuilt so I'm not sure why this is happening. I baby my truck.

I have the 4R70E in the truck now, will the 4R100 fit? It's suppose to be a heavier duty tranny correct? If it will does anyone know where I can get one and if not where I could send mine to have it reinforced?

Thanks.

 

For $3200 and just 6 months, I would have the local shop fix their lousy re-build job.

 

That's where it is now. I'll see what they say in the morning.

I inspected underneath and oil is leaking out of the converter housing access plug. The whole underside of truck is covered so whatever went took out a seal. Maybe the pump seal, not sure what other seal would fail and cause the oil to come out the access plug.

They replaced clutch pack etc. last time and I would expect it requires replacing again from the smell of the trans oil.

Lets see if they stand behind their work and actually fix it.

 

I had a 5R55W rebuilt about 15 months ago at a local transmission shop for around 3k. They guaranteed it for 12 months and that came and went and the tranny is still working good and these are known beasts. I would think if your shop is reputable they will make it right. Remember the squeeky wheel gets the oil, raise hell if you have too. That's alot of money for poor quality work. They obviously didn't do a complete rebuild (they should have for that kind of money) or they made a bad mistake on something. Good luck and keep us posted.

 

Its a real shame so many shops out there charge top dollar and then do such a crappy job. I lost my stock transmission when I hit 520hp. I was ok with it because I knew it was coming and was already researching built trans. Anyway there is more to a rebuild then simpling replacing the parts that come with the kit. Only a few shops follow these steps. And per Fords tsb its a must. For one if any clutch materials are in the fluid from either the torque converter failing or a trans failure you must flush all lines. The thermal bypass valve which is in the trans fluid lines by the starter must be cleaned and/or replaced, the lines must be throughly flushed or replaced, radiator replaced, trans cooler replaced, torque converter replaced, and an inline filter must be installed. The reason for all of this? Clutch materials released stick to everything inside. Literally the crap is like anti-seize. You cannot clean the inside of the coolers hence why they must be replaced. A flush will not do the job. However in some cases the radiator is flushed to save money but its risky. The cooler has smaller passages and cannot be flushed clean. Any clutch materials not removed whether by flushing or replacing the part can be released by the flow of trans fluid after the rebuild. These materials pollute the system and will cause a premature failure usually within the first 1000-10,000 miles. Ford and Chrysler added the inline filter to their tsb's in the 90's after a number of repeat failures as a little insurance that if some materials remained in the line some where the filter would catch it and prevent another failure. GM probably did to but I have never seen the paperwork so I can't state it as fact.

 

Yeah it looks like the pump seal blew out into the bell housing. Not sure what would have caused this to happen. Maybe not installed properly? Is there any way for the pressure to build up sufficiently to cause this?

The shop went good on it but if it happens again I won't be covered.

As per TwinSkrewd's post, I doubt they replaced any of the hoses or cooler and definitely no inline filter. FYI I had 9,000km on since the first rebuild...

 

The shop went good and rebuilt the tranny as I mentioned in the previous post when the seal went.

It's now been a few months and it appears to be leaking out of the seal on the input shaft again (I keep refering to it as the pump seal previously). I see a little bit of tranny fluid around the converter housing access plug.

They apparently replaced everything and couldn't tell me a cause.

I haven't driven my truck hard or towed, no programmer.

Anyone have an idea what would be causing this? I can't afford to replace or rebuild a transmission every 5-6 months.

Thanks.

 

And does anyone know if the the 4R100 will just bolt in?

I might be replacing this again soon...

I have a friend that I should have taken this to in the first place to have rebuilt but the timing wasn't good, he'll do it for half the price but I still don't have 1600 bucks to spend on it again.

 

Tranny's are hard to deal with as not many people know all the workings inside and out. I hope you can figure it out but this sounds like maybe something is getting blocked in a line somewhere and building up quite a bit of pressure and then as the tranny heats up and doesn't get enough fluid to cool it and keep things greased the seals may be showing the excessive heat and expanding which then pushes fluid out. I have not idea though as I am not a mechanic just trying to make sense of the issue you have. Hope you get it figured out soon and it doesn't cost an arm and leg.

 

Yeah, there is a vent but if it's plugged I was told it would push the dipstick out to relieve the pressure.

I can't find anyone where I live that works on transmissions that can even guess at a possible cause. Everyone just shrugs and says they have no idea.

 

BigD, where do you live?



CMOS

 

His profile says Ont. Canada

 

Thunder Bay, Ontario, Canada. Small city, about 115,000 people and the nearest large city (Winnipeg) is 7 hours away.

I would like to find out what is cause this before it goes again. Winter's here and I'll be driving all over with my sled in the back to go riding and rather not have it go in the middle of nowhere.

I've thought of having the seal and torque converter replaced to see if there is an issue there. Maybe something is warped that didn't get replaced?

Either that or I wait until it goes again, burns out the clutch pack and I start over again with a new, different rebuilt tranny and hope for the best.

I just can't trust my truck at all anymore...

 

The slightest burr on the sealing surface of the torque converter (that part that sticks inside the trans and which the seal wraps around and tries to seal to) will quickly eat up the lip of a seal.

The only way to "know" is to pull it out. It could be as simple as an accidental hit with a wrench, a bump while it was out, etc.

Problem may be a mechanic not thinking to check the surface, or ashamed that he maybe damaged it? I wasn't there, I don't know you or the people working on it.

A new TC can be damaged by careless handling.

In either case, if it was new or used and the sealing surface is burred / knicked ...
... it will require a new TC and seal ... and care on the install.

 

yeah thanks for the info tbear. I was thinking that it could be a burr or something like that as well.

I can get a TC for 160 bucks after exchange and the seal isn't too bad either so I might just go ahead and replace them and see what happens...