Saginaw 4 spd.

Wondering if you guys know anything about the Saginaw 4 spd. I found a guys that's got one and was wondering if they are any good. He said $300 for the tranny and tcase adapter.

 

If we're talking like an m21-m22 4 speed for a car, they are tough but have crappy gearing for a jeep and alot of them were aluminum cased which I myself consider a serious weak point for a jeep. I personally would lok fof a more suitable truck 4 speed like an sm420, sm465 both (GM) or a t18 borgwarner (Ford) or an np435 (Chrysler), these are all iron cased have a very low (granny) first gear and are virtually indestructable in a normal jeep, if you want a 4 speed like the Muncie units try a t176 borgwarner as they were already used in a jeep and work fine but have better gearing than the car transmissions.

 

sss

My 71 had a Saginaw in it when I bought it. Best thing I ever did was losin' that thang. External linkage was always getting bound up or stuck or had crap jammed in it. Wasn't anything to do with the frame cracks though, I'm sure. I truly didnt like the setup. My opinion.

 

If memory serves, GM did have a muncie in the truck line............early 70's I think, behind the I6's in the 1/2 4x4's.

 

Saginaw 4 speed has a cast iron case. In something light like a Jeep they work fine. Been running one in the '59 since 1989 and works great. There are different first gear ratios in the Saginaw. My is the widest ratio available and has a 3.8-1 first gear. They go clear up to something like a 2.4-1 first gear ratio. There are 4 different stock ratios available with the other two ratios in between the two I just mentioned. I like mine as I used to race it and still run sand dunes quite a bit and it is a quick shifting trans, unlike the truck tranny's. Down side is it isn't as bullet proof as the truck tranny's and can't get as low a first gear. Parts seem to be slowly getting harder to come by as well. Another down side is the linkage issue. They are a side shift trans with external linkage, and can get crap built up in them as Wheelie mentioned. I have to periodically take mine out and flush it out thoroughly, lube it up again, and re install it. Kind of a pain. Check out the first gear ratio of that trans. If it is low like the 3.8-1 first it will work great. If a tall ratio like the 2.4, you probably will not be happy with it. Good luck. Nickmil.

 

The Muncies and T-10's I will agree are wrong geared for a Jeep unless running sand or racing. See above post about gearing of the Saginaw. 3.8-1 first gear is significantly lower than almost all stock Jeep tranny's with the exception of the wide ratio T-18/T-98. The close ratio T18 only had a 4-1 first gear! Behind V-6 power the Saginaw will hold up fine. I've never broken my Saginaw ever and used to race the Jeep and I run 33" tires with a warmed up 231. Have rebuilt it several times though. You definitely don't want to thrash on pavement though, just like you said!
Nickmil.

 

Aww, you're making me blush! Lots of good info out there! You all contribute great info! Just happen to know a little bit about manual tranny's is all. Nickmil.

 

Siginaw 4 Speed

Yes, I ran one in my Nissan 4x4 Pick-up behind a 231 even-fire Buick V6. I ran a short driveline to a divorced T-case.

From what I understand Novak used to make adapters for Jeeps for these.

They have all syncros in all 4 speeds--- but have no advantage for trail driving over something like a t-90.

These were adapted because some Jeep owners wanted a transmission better suited for stop and go street driving.


I sold my old Siginaw at a garage sale to a guy in my neighborhood who put it in a 1968 Camaro last year for 20 dollars.

He burns rubber with it every morning when he peals away from the stop sign at the my corner lot, on his way to work. So they have to be pretty strong.

 

Re: Siginaw 4 Speed

 

I had the saginaw in my 69. I took it out and put in the 465. I sold my old setup with shifter adapter and everything on ebay for $200. I am running 5:38's in the diff's, with 31" tires. With it being such a close ratio 4 speed in a light vehicle, it just never seemed geared quite right. I am definitely looking forward to trying out the 465.