48RE Vibration Problem

[Bernie]

About 6k miles ago I got some work done to my transmission:

-I got a Goerend valve body

-I got a new Billet TC (from local transmission shop)

-I also had the lever, apply strap, and anchor band replaced with Goerend parts when the shop did the work.

-The trans shop did some other small work they felt was necessary or a good idea (I think a band, some seals and other stuff. The bill was reasonable so it was nothing major).



-I left the trans shop, drove 200 miles, and hooked a small (single car open, about 4000 lbs) trailer to the truck and drove for 2000 miles.

-Then, I drove another 1500 miles with a 12k lb enclosed car race trailer. This was fairly hard towing, with a lot of stop and start, all over Newfoundland Canada.

-We then hooked our single car trailer back up and headed home.

-When I was towing the big trailer, and later after a particularly long tow (about 12 hours nonstop) I started to notice a vibration in top gear at low RPMS. The problem goes away when you drop a gear, or add RPMs. It is most noticeable around 50 to 60 MPH, light throttle input, with a load.

-The problem is now worse, and shows up with out a load on the truck.

-In total I have put about 6k miles on the truck in the three weeks following the trans work!



As we were on the road, we drove around the problem. I am now home and (finally) caught back up on work so I am just now getting back to truck stuff.



I'm new to Autos, so bear with me

-I don't think this is a TC problem, or it would happen in all gears. Is this correct thinking?

-Could it be a valve body problem?

-Could it be a band problem?

-What else could it be?



I have a call in to Goerend. They called back with in 10 min, but I was busy at work and couldn't answer. I'm sure they will try back soon. I also have an appointment at the trans shop tomorrow to get their input. I just wanted to see what the TDR masses thought so I would be a little better educated when I talk to Goerend and the trans shop I used. Thanks!

 

[Bernie]

Almost forgot, the rest of the powertrain is stock. I now have 112k miles on the truck.

 

[Bernie]

Goerend is a great vendor

Just got off the phone with Goerend. I know it has been said before, but this an exceptional vendor. He just spent 30 min on thone with me explaining all the possible problems. and the fixes to those problems.



In short, he feels it is probably a slipping TC. I will let you know what the trans shop comes up with.

 

[JamesStevens]

Sounds like you have it sorted out, that is good

I just had a bunch of transmission work done (ats stage 4 put in) 48re, and mine is a little wobbly at idle, but fine above idle. I think the flex plate is not balanced.

 

[Bernie]

Forgot to update:

-Trans shop thought it was the overdrive clutch pack or the TC.
-Left the truck overnight.
-Trans shop replaced the TC. Warranty. No charge.

However:
-I think, with the exception of the vibration in overdrive, the TC that was slipping in overdrive felt better everywhere else.
-I have only put about 300 miles on the new TC, but it seems to slip more than the one with the obvios overdrive problem that came out.
-Is there another adjustment that could need to be addressed, or is there that much difference in the "feel" of different serial numbers for the same make/model converter?
-Also, MPG seems to have dropped from 18 to 15. 5 with the new converter.