what could cause harsh 3-2 and 2-1 dwnshft on 5r55e?

[robrike40]

Hi all,
I had the 5r55e rebuilt last year on my 98 XLT with v-6 SOHC. Came with 12 month 12k mile warranty. Warranty has about run out and I have a intermitent harsh or abrupt 3-2 and 2-1 downshift. It is sporadic and no obvious culprits such as cold or hot, etc. I am taking it in Tuesday to let them check it over but just wondered what to expect them to look at? Other than that it runs great and shifts up just fine and 60% comes down fine. Another thing is that when going from r to d or d to r I have to put in in neutral for a couple of seconds at a dead stop or it will engage reverse or drive with a clunk. I never shift from reverse to drive or vice vera unless at a complete stop but if I don't let it sit in neutral for a second or two in between it is harsh. Are these releated problems?
Thanks,
Rob

 

[BrooklynBay]

Are your RPMs high?

 

[robrike40]

No, that is the weird thing. There is no CEL or overdrive flashing, all seems well. When going from r to d or the otherway around my rpms are usually in the 700 to 800 range. Now that I think about it, when going from park to reverse it tends to clunk. Almost like a bad u-joint but if I give it that little extra second or 2 in neutral before engaging reverse (assuming I had been in drive) it is not harsh hardly at all. If I just come to a total stop and switch, I get the clunk. And the 3-2 2-1 clunk sporadically seems weird too. Could it be something as simple as a bad u joint or a band adjustment? It is still under warranty so I just want something to go by when they tell me what they find or do not find. When it was rebuilt I had already put the transgo shift kit in, I would not think that would cause a problem 11k miles down the road.

Right now I have sprung a coolant leak near my thermostat housing. Planning to pull the intake to get a good look at it and fix that. Hope to get that taken care of tomorrow so I can run it back to the trans. shop Monday. Warranty is about to expire.

Thanks as always,
Rob

 

[Davek1]

where did u get your tranny from cause when i am drive and come to a stop sign i start braking and when the speedo gets to about 30 it clunks and the abs kicks in for a breif second

 

[robrike40]

I had my original rebuilt locally in Tennessee. Had 206K on original. Cannot complain but in the last few months the harsh downshift has started. The rebuilder offered 12/12,000 warranty and it is almost up so I want themt o fix it ASAP. My ABS does not kick in but I do get a jolt around 25 to 30 on the 3-2 and another around 10 mph on the 2-1 downshift. I will keep you posted on what I learn.
Rob

 

[BillJ]

Check out these links for possible reasons:

http://autorepair.about.com/library/ts/at/bl-at-15.htm

http://autorepair.about.com/library/ts/at/bl-at-13.htm

http://autorepair.about.com/cs/troubleshooting/a/aa072702a_3.htm

Was the EPC solenoid changed when it was rebuilt?

 

[robrike40]

Hey Bill,
Yes, the EPC was replaced after the rebuild as there was still a 2-3 flare the tech was not happy with. He put a new EPC in and all was well till this downshift problem started.
Rob

 

[BrooklynBay]

Maybe your hydraulic pressure is too high. Most of the time these transmissions suffer from low pressure, and have very soft shifts. There might be a valve body problem causing this. I would suggest that you have the shop use a 0-300 PSI gauge to test your pressure. Post the results in all gears ranges (P, R, N, OD, D, and low).

 

[BillJ]

Hey Bill,
Yes, the EPC was replaced after the rebuild as there was still a 2-3 flare the tech was not happy with. He put a new EPC in and all was well till this downshift problem started.
Rob

I would have them drop the pan, retorque the VB, adjust the bands, test the EPC and perform a pressure test as BB recommended.

Good Luck,

Bill