Well, coming home friday night it happened to me.....

Driving along at 60 MPH just started to Rev and loose speed.

No 5'th gear.

So I'm assuming my 5'th gear nut backed off and I gotta fix it.

How big of a job is this??

I understand you have to drop the transfer case and take the back of the transmission off?


Any special tools required? Local supplier quoted me $82 dollar for the nut. When I asked about labour to do the job he said toatl including parts would be $600+ so I figure I'll be doing this one myself. Way to mess up any Christmas plans.

 

The fifth gear problem is not just the nut working loose, it is highly recommended you also replace the shaft on which the third gear itself rides. The OEM shaft has a short spline on which fifth gear does not fully engage.

For all practical purposes a guy trying to do this in his garage should allow a day to do it right, and about two hours to do the nut fix only.

For the nut fix only you will need to pull the transfer case, remove the adapter housing from the tail of the transmission, and cobble a fix by installing a new nut or just reinstall the old one and tack weld it on the outside edge of the adjoining threads. For the guys that want cheap, I just reinstall the old nut and weld it after it is properly torqued, and it works better than the best locking nut you can find.

To do it right it is much simpler to just pull both the transmission and transfer case and then remove the transfer case. Once that is done, disassemble the transmission and replace the third gear shaft with one of the aftermarket units that has the full spline. Given you have a 99, I would do the latter and replace the syncro's while I was in the thing, and also check the rear main shaft carrier bearing - they do not get adequate lubrication and get pretty sloppy over time. Then thread the oil hole for the rear main bearing and install a street el with the elbow turned up so it catches the oil that is flung up by the gears and directs it to the bearing.

The reason that the fifth gear nut fails is that the shaft actually torques just like a torsion bar from the gear only riding on about 9/16 spline length. That forces the nut against the bearing and eventually will work it loose. Once the fully splined shaft is installed, the new shaft will not torque and try to press the nut off.

 

Yeah, I looked on the quad 4x4 site and the main shaft assembly is not available on it's own anymore?? I think it says you can only get it if you buy their Rebuilt unit.

Can you replace the shaft with the tranny still in the truck.

I don't want to pull the tranny again.