Thread: TD6 Shudder problem

Yep, I've recently had a fully rebuilt tranny and a brand new transfer case installed and I have a slight shudder, normally on cruise control at about 80-90 km, in top gear when approaching a hill, before kickdown, it's gearbox, not engine...not sure quite what though!

When the gearbox was re-built did they replace the torque control solenoid in the box ? This is responsible for lock-up in the torque converter; if it wasn't operating properly than slippage or shudder could occur.
This was one of the items we discussed in the H/D rebuild of the 5L40E a few pages back.

https://docs.google.com/viewer?a=v&q...QcDLvo3cC7rw1A

I have no idea if they have replaced this item but I will inquire. Thanks for the lead.

Originally Posted by Summiitt

Yep, I've recently had a fully rebuilt tranny and a brand new transfer case installed and I have a slight shudder, normally on cruise control at about 80-90 km, in top gear when approaching a hill, before kickdown, it's gearbox, not engine...not sure quite what though!

Was there any sign of this shudder before the original transmission failed?
I certainly had not experiened it previously.
I have only had a test drive at the auto shop but it came in as I was gently accelarating and at the same speed range as your car is experiencing the shudderer at.

Hi Uteman,

I have the exact same problem and over the last few weeks have tried to sort it out.

I had a fuel system problem causing a different type of judder so got this fixed first. replaced low pressure fuel pump and no1 injector and injector harness.
with that fixed ok I took it to the auto transmission guy who is great and i trust him 100%. he agreed that it was the convertor playing up when trying to lock and unlock. he gave me the option off a new convertor and a check of the gearbox when it was out. but all things considered with my car having 215k on the clock i would be up for a gearbox and convertor at approx $7k, which seems about right.
He rang me when he dropped the sump and said the fluid was low and dirty and recommended a flush and service to see if we can get a few more klms out of it.
with this done the changes are a lot better and the delay going into drive when cold has gone. but the convertor judder is still there.
I have learnt to get around this problem by knowing when its going to do it and moving the stick over to sport mode as this unlocks the convertor without any juddering at all. even at 100kph this doesnt rev too much and works a treat.
the auto guy says see how it goes and if we can get another 12months out of it then great as he doesnt reckon it can do any more harm and wont suddenly break down on me.
Ive done about 4k since and its going great as long as i manually unlock the convertor when required.

hope this helps

neil

Have you tried using Manual/Sport mode to compare the gear changes ?

If the shudder disappears when using sport mode it's a fair indication of a drop of "inline pressure" ! As this mode increases line pressure for the performance gear changes.

Laurie

Laurie: I will have to either get the shop to try this or travel there again for a further test drive but one way or the other I will check it out and get back to you. Thanks very much.

Uteman
I forgot to ask initally, BUT did they flush the oil cooler system when the gearboxes failed ? if they didn't any debris would have been sent back to the T/C, pump and valve body and the breakdown of metal would start again straight away. If they didn't flush the system I would be asking for a full warranty re-build. These GM boxes are a nightmare , hence our seeking a alternative !

Laurie