So after about 6 months of procrastinating I finally got the Getrag out of my 90. It was popping out of 3rd once and a while then it started doing it in every gear. By the time I got home I had it stuck in second so I pulled it in the shop and there it sat till today. When I took off the transfer case the adapter was full of oil. It had pushed the seal out the back of the tranny. I drained the rest of the oil out and it definitely had some filings in it but there were no chunks. Seemed like a small positive. I took the top cover off before I quit for the night and could not see any real damage to any thing except for the shift forks. They look like they were worn. very sharp edges with little slivers, likely the source of the filings.
So I guess my question is, what pushed the seal out and was it the lack of oil that wore the shift forks? Any thoughts on stripping it down and replacing bearings and seals myself. Rebuild kits seem pretty reasonable. Any help would be greatly appreciated.

 

I would definitely tear it down and put new bearings, syncros and shift fork in. Perhaps the vent was plugged and caused the rear seal to blow out?

 

I don't see a vent on this case. At least it's not on top of the cover by the shift tower.

 

I've never had a Getrag, so I'm just going by what my NV4500 has. Just assumed it would have a vent out the top somewhere?

 

My 93 has a vent it's up front by the shift tower if I remember correctly but this one doesn't. I believe it is the original Getrag that came in the '90. Almost 300,000kms pulling 20,000lbs. So as far as durability goes I can't really complain. I would how ever like to know what pushed that seal out though. Could have a bad bearing caused that seal to walk out the back. Seal looks to not be in too bad of shape.

 

I had a chance tonight to tear down the Getrag(mostly anyway). Input bearing was toasted and it chewed up the front bearing retainer. I am thinking that it also was responsible for chewing up the shift forks. The 3/4 fork is right at the front of the case and it took the worst of it and I think that I will replace it. The 1/2 fork is in the middle and is scored ever so slightly, so I think it can be reused. The 5/rev fork is at the back and looks untouched. Gears all look good. Hopefully I can get the main shaft disassembled tomorrow and have a better look at the syncros. Not entirely sure how to decide if the syncros are good or not. Can't say as I have ever tore into a manual transmission before. Any words of wisdom would be appreciated.

 

I'm watching this thread as you update it and people chime in.... I fear my g360 is starting to fade on me. So I'll have to do somethig in the near future.

Good luck with the rebuild

 

I am watching aswell, tearing mine apart in the next week. Minimal damage in mine I think but figured I will replace some stuff while it is out.

 

Talked to Protracgear in Edmonton about parts yesterday and going to order parts today from them they were very helpful. I needed two shift forks so I had him build me a new shift tower. I will also need a bearing kit, input shaft, front bearing retainer and the syncro ring on first gear. A mechanic from town said to use muriatic acid to clean the aluminum out of the shift collars. So I'm going to try that, but if that doesn't work I will need collars for 1-2 and 3-4. Also going to order a new pilot bushing. And for what it's worth try not to take apart the 1-2 syncro. It is a real pita to put back together.

 

A tip to put those little ball bearings back in place for those tricky syncros is using vaseline. Put a dollop of vaseline where the spring and ball ride, stick it all in there and use your thumb and middle finger on your right hand, and another finger on your left hand to depress them all while sliding the shift collar downwards.

It's hard to explain over the internet but I found it really easy once I figure the first one out.

 

Thanx for the tip, I am going to get the aluminium stripped off the slider and try just that tomorrow night after work. Tonight I took the case and bell housing over to a buddies house and used his Hotsy to clean the years of grime off them. I talked to the guy at Protrac and parts should be here on the weekend. Another helpful little hint for anyone trying this on their own a press is very handy but probably not 100% necessary. The bearing on mine at least didn't take that much force to push off. You could likely make do with a good puller set. But a good heavy duty snap ring tool will be your friend. Also I think that if I would have pulled it sooner I likely could have got away with just bearings, seals and one syncro ring. Probably about $220 and opposed to the $600ish that this will cost. So if this goes well I think that this summer I will do the '93. So far the hardest part has been getting that big hunk of pig iron out of the truck.

 

I had quite the time wrestling with mine with the np205 attached still, with no helper

Do you have the pdf of the rebuild manual?

I'd also advise a good depth micrometer and regular micrometer to get your pre-load to exactly what the book calls for.

 

Yes I have a rebuild manual and I did take a few pictures while I was taking it apart. I built a bracket to bolt to the transfer case so it sits on the jack nice and split them. that looked way too hard to do as one piece. I also have a good dial gauge coming to measure bearing preload. The guy at Protract said to use the same shims that come out, that they would more than likely be right, but I will still check.

 

I think my BS alarm just went off.

 

He said that more times than not if you don't change the main shaft that that original shims will be what you need. I will start with what came out and see where I am at and go from there. It seems to me though that I read somewhere that some of the first rebuilt G360s were set up too tight. Either way I will be checking the clearance to make sure that it's right.