NV3500 rebuild

[cabledawg]

How hard is it to rebuild a NV3500 trans? Second gear doesnt work at all and first wont go in unless the truck is almost stopped. the other gears work fine.

And no I have no intentions of upgrading to a 4500. I bought the truck for $200, it just needs to get me from home to work and back.

 

[Hogback Fabrication]

Are you sure the clutch is disengaging all the way?

If the trans needs a rebuild, its not too tough.

 

[cabledawg]

Well I thought this at first. I bought the truck from a friend of mine and he thought the clutch pack was bad, so he never drove it. So last week I decided I'd mess with it to see exactly what was going on. At first the truck wouldnt go into any gear but second, and once the clutch was out, it still wouldnt do anything. Now if I shut the truck off, put it in gear, then start it, I'm fine with 1,3,4,5. In order to back up, I have to shut the truck off, put in reverse, start it then drive.

So today I went and bought a new clutch pack and got it installed. I didnt line up the throwout rod with the fork and blew the seal on the slave. I mnanaged to fix it so it wouldnt leak anymore and blaed the system. So now the truck will go into first without shutting it off, but I have to be pretty much stopped, cant even float the gears. Second doesnt work at all. It'll go into the position, but nothing happens as if its in neutral. all other gears work fine 3,4,5,R all work like they are supposed to.

I wonder if the shift fork for 1-2 is jacked up, but either way I'll need to tear into it, so I might as well rebuild it. I've never torn into a trans before and just need to know if there are any special tools required, or will average joe type stuff work. And for what I found for rebuild kits, I can buy a used trans, so I might just go that route and use the bad one as a learning tool. Basically if I f*** it up, I'm not out a vehicle (cuz out of the four I own, none are 100% fixed)

 

[tRustyK5]

It may be the 1-2 fork is nuked in some way. The alternative is the dog tooth mechanism that the fork slides to engage 2nd gear is hashed...which seems less likely. If I remember right that tranny is integral bellhousing and splits right down the middle...so it may be easier than most manual trannies to disassmeble and repair.

You may need a press for some stuff. You will need some big snap ring pliers (most likely). I rebuilt my NV4500 from catastrophic basket case a couple of years ago having never done one before. The only thing that really helped me was the exploded views I found online.

Definitely replace all the synchro's...

Rene

 

[cabledawg]

Thanks for the input. I dont have a press now, but I might buy one after I move later this year. The trans does have an intergral bellhousing and from what I noticed it seems to split down the middle. I havent been able to find any good exploded views of this trans, but if I find some, I'll be sure to post them.

 

[tRustyK5]

Being this is low budget stuff I'd split the case and have a look see before buying anything significant tool wise. If at that point it looks doable...I'd still look at taking stuff you need a press for in some place and pay the $20 or so they'd charge.

The only part I needed a press for was installing the input gear bearing, so I took it to work and did it there (and fukked it up...had to buy another bearing and do it again )

Big snap ring pliers were a godsend though.

I haven't had a 3500 apart, but on the NV4500 the mainshaft and the countershaft ride on tapered bearing at each end. This requires the use of shims at the back end to set the end play up to within limits. A dial indicator with mag base, plus some digi calipers helped a lot to get this part as correct as I could get it. The 3500 might be different...but just so you're prepared you may need some accurate tools too.

Anyways, good luck and let us know how it goes. I can honestly say I understand fully how a manual tranny works now. i don't regret doing the NV4500 at all, even though in the end it would have been the same money to just buy a good one.

Rene

 

[Thunder]

Not hard at all to rebuild a nv 3500. Simply replace the POS with a NV4500.
All fixed! That is what GM did after they realized their mistake.

But if you want to fix it. Pull the tranny, clutch, and replace the pilot bearing in the flywheel. Sounds like it is bad

 

[cabledawg]

Replaced the clutch pack, TO bearing and pilot bushing. The old PB and TO bearing were trashed. The clutch plate wasnt much better. Worn down almost to the rivets. I didnt notice any play in the input shaft and nothing was leaking out of the trans.