T90 Rebuild question: removing the reverse idler shaft

[jake138]

Good afternoon folks,

It's come time for me to rebuild my T90. I just recently finished the transfer case after following Rick Stiver's guide, and so I started using Rick's guide for the T90 as well. Here's where I've stopped:

Rick's guide for the T90 states to drive the reverse idle gear shaft from the inside of the case to the outside. However, while perusing the internet, I found this fellow:

https://willysjeepforum.kaiserwillys.co ... vers-Guide

And he seems quite adamant about the fact that Rick's guide is wrong, and that the reverse idler shaft is much more easily, and properly, removed by hammering it from the outside of the case into the inside.

My question is to anyone here who has rebuilt their own T90: which direction did you remove the reverse idle gear shaft?

Although this guy is the only person I've seen so far to contradict Rick's guide, I'm curious now if people have pressed their shafts into the case if they were not following Rick's guide.

From a manufacturing standpoint, I can see how it would be easier for them to assemble the T90 at the factory by pressing the shaft into the case from the outside. Looking at pictures of new shafts, it looks like only the end nearest the locking plate is of a larger diameter that presses into the case, which would then make sense for the shaft to be pressed out from the inside of the case towards the rear.

[Mike_B]

Jake,

I've done (2) T-90 transmissions in the past few years and I drove the reverse gear shafts out just like Rick shows...using small punch on the inside and drive them out.

I'd be worried that driving the shaft in could cause it to bind up inside the case due to a rough edge or bur on the outside end of the shaft, causing more grief than necessary.

Hope this helps.

Mike B

[4x4M38]

Hi Jake,
I can’t remember it’s been over a year. But I thought U read that shaft has to be removed and installed only one way, because of a taper or slight diameter change. Hammering it the wrong way could damage the shaft but more likely the case.

[4x4M38]

And do yourself a favor and make those wood dowels. It makes rebuilding incredibly easy.

[jake138]

I'd be worried that driving the shaft in could cause it to bind up inside the case due to a rough edge or bur on the outside end of the shaft

Judging from pictures of new reverse idler shafts online, it looks like the shaft has a larger diameter at the outside end, leading me to the same conclusion as you.

I'm imagining that if that larger diameter can even be pressed through the gear itself, it is not going to want to be pressed through the boss inside the case.