5spd from 88 IFS in an 87

[bigblzr]

hello, i am new to this forum. i was wondering if anybody has ever heard of someone putting a 5speed from an 88 4x4 pick-up into a 73-91 blazer. i did the sm465 conversion to my last truck and it was a cat's ass thanhks to this site but i need something with overdrive. thanks

 

[79k20350]

there are a few whove done it. search around a lil to find all the answers you need. bolts right up to the motor. depending on the tcase it may be more work there. also they have a real bad 5th gear problem. always remember, the search button is your friend!

 

[K5er4Life]

I wouldnt want to run it in anything but a stock application, not to say they are bad trannys just not nearly the strength that you will get out of your 465. I think there called the "getag" or something like that. I have one in my 1/2 ton work truck and I have blown it up once kind of twice. I dont know exactly what happened to it but once the clutch took a dump (broke apart when downshifting) and the second time I lost third gear altogther and made a horrible grinding noise. I think theres a reason why people are going through the trouble to run a nv4500 or 465 instead of those weaker transmissions, even though they are very plentiful.

 

[79k20350]

I wouldnt want to run it in anything but a stock application, not to say they are bad trannys just not nearly the strength that you will get out of your 465. I think there called the "getag" or something like that. I have one in my 1/2 ton work truck and I have blown it up once kind of twice. I dont know exactly what happened to it but once the clutch took a dump (broke apart when downshifting) and the second time I lost third gear altogther and made a horrible grinding noise. I think theres a reason why people are going through the trouble to run a nv4500 or 465 instead of those weaker transmissions, even though they are very plentiful.

he might mean the getrag but i though he was talking the nv4500. dont know anything about the getrags. the 4500 are great trannys save for the 5th gear problem.

 

[73k5blazer]

Sorry to hijack, but I see this all the time,people saying 5th gear is bad, and just have to ask, what IS the "5th gear problem" people mention with the NV4500? My '97 K2500HD with 6.5TD has just under 200,000mi, and has been worked very hard on and off road, my buddies '97 1ton with 454 has well over 200,000mi,both have NV4500, and niether of us have ever touched in the inside of ther tranny. Replaced clutch a few times, but tranny works perfectly. Shifts smooth as a babies a**, all gears. I search around but can't find what the "5th gear problem" actually problem is.

In reply to original post:
If it's an '88 it's probably just the nv3500 5sp. Not so robust for an off-roader.

 

[79k20350]

the problem is the nut that hold 5th gear in place can come loose, fall off and cause big problems. thats the jist of it anyways. doesnt seem like all trannys do go bad but it was an inherant deign flaw so any could have this happen.

 

[tRustyK5]

'88 would most likely have the predecessor to the NV3500 otherwise known as the Getrag. As noted they're not that strong. The NV4500 didn't intro until '92 sometime.

The 5th gear problem you can read more about here:

http://www.quad4x4.com/NV4500%205th%20Gear%20Failures%20and%20Solutions.htm

High torque diesel applications being used primarily for towing heavy loads seem to be the most suceptible. With a heavy load imagine the throttle closing during decel, then being applied again. When new it's all good, but over time and heavy use 5th gear starts to rock on the splines of the mainshaft. With a nut on the other side of it the rocking of the gear backs the nut off over time. There are easily a half dozen aftermarket 'fixes'.

I think that the majority of the trucks that have had this problem were using it beyond design limitations...either too high an input torque or towing more than the recomended max (or both)

I'm rebuilding an NV4500 right now and have chosen to use the stock nut. There were no signs of fretting on my mainshaft and that nut was tighter than a fish's a$$ when I took it apart. I don't tow, and the mighty 6.2 I have isn't much of a threat to 5th gear IMO. On my particular tranny there is also a harmonic balancer between 5th gear and the nut further insulating the nut from any possible gear rock.

Rene

 

[73k5blazer]

That's very interesting. Thanks. My '97 is a 6.5 diesel. I tow a 4 place enclosed snomobile trailer (a pig) at least 4-5 times 16hours round trip per winter season, as well as various other loads throughout the year. Not the heavist load I'm sure, but that trailer with 4 sleds and gear is a friggin pig to tow. I leave it in 5th almost exclusivly too on the highway, which is what most of those snomobile trips are on. Now I will worry, so mabey I shouldn't thank you. Well, I asked. My fault.

 

[tRustyK5]

The good part is that 5th gear is pretty easy to get to compared to any of the other gears.

Rene