Thread: No 4th gear. Fix or replace?

yup, time for a new trans or rebuild yours.

It sounds like a bad 4th clutch hub.

It's possible to replace just the shaft. Thing is ..it's about 3-6 hours of work. And then..what's the condition of the clutches etc. If it were my car, I'd replace just the hub, because labor is free doing your own work.

Mines at around 2400 on the highway but I'm guessing it's 3.29 gearing

Does the clutch hub include the shaft and the clutches? Looks like only $40 on ebay. Is this it?: http://www.ebay.com/itm/4T65E-97-4TH.../330558555231?

ebay item number 330558555231 if the link doesnt work.

That's not a bad price if this is the part you are talking about. Just need to find a shop to put it in for me.

that's the one and no, the clutches don't come with it. Just the shaft is technically what GM calls the clutch hub shaft.

You'll also need a set of channel plate gaskets.

Actually..you won't be able to see much else to replace. The 4th clutches will be nice to have. keep in mind there's a slightly thicker steel that goes in first and is called the apply plate. Replacing the 4th clutches is a choice,

If you can..locate 2-4 long M6 x1.00 bolts. Say 60-80mm in length. Cut the heads off them and when you pull the channgel plate/VB as one unit, use them to hold the channel plate gaskets in place. Also..they'll help you guide the channel plate/vb assembly back into place. I put them in a couple threads only so that I can take them out by finger later.

To pull the trans apart to do this.. I like to do this.
Drain trans fluid
Support motor from above.


Unhook endlinks
Pop both balljoints
Remove 2 18mm bolts holding ps rack to subframe
Unclip ps cooler line from subframe
Remove any plastic clips holding wiring to subframe
Undo two 15mm nuts on engine mount to subframe and 2 15mm nuts holding trans mount to subframe
Lower subframe (4 x 18mm bolts)
Pull driverside axle
Remove as many trans side cover bolts as possible
Now lower the motor/trans (tilting a little to the driverside if possible)
Remove any remaining side cover bolts and lower assembly until you can wiggle the cover out.

Gently unhook the wiring harness for the trans


Unhook the valve slide that is connected to the shift cable (in this pic on the lower right, see the metal rod? That's what you need to unhook at the end we can't see that is under a soleniod.)


Remove the pump from ontop of the VB (black screws only, leave that silver one in to hold the pump together)

Pump off


Remove bolts 230, 231, 377, 805, 433, 434, 435, 436, 374, 379, 380, 384



This will get the VB/channel plate as one unit.
Replace hub shaft, clutches (if applicable) and channel plate gaskets.



When doing the gaskets. You'll notice there's one pin at the end of a long gasket. This is where the spare M6 bolts come in. Looking at the vb/channel plate combo, determine where you can put a bolt and still take it out once the assmebly is back in palce.

Here's the 4th clutches, the part they engage in the middle is the hub shaft


Removing the clutch plates, pull the shaft and note a plastic shim/bearing on the shaft. The nubs of that sit in the drive gear where this came out of.


You will likely need to vigorously wiggle and turn the new shaft to engage it in place. Then put the clutches back in place (note orientation of the notches etc as the channel plate has to clear them) and it'll all go well.

One thing you can check while you are there is the drive chains. You pull them with a finger toward the bottom of the case and the measurement to resuse changes IIRC needs to be 1/8" or more.



More pics here Login to a private Photobucket.com album
Password if needed is "Boosted"

I even made a how to for the how to section. It's not every single step in detail, but it should get you through it if you have a couple wrenches and whatnot.

PS.. balljoint nuts are 18mm and that ps line bolt at the subframe is a 10mm