Swap to 4 speed???

[rkymtnflyfisher]

4 speed tranny in my 74 is bolted up to a 3 speed bellhousing, with stepped flywheel annd 3 finger clutch. 74 was the oddball year when they started to introduce the 4 speed tranny.

Maybe my bellhousing is a 4 speed? It is a possibility, I was under the impression that the bellhousing, flywheel, and clutch all had to match.

I could be wrong about this.

 

[jcj_78FJ40]

Sounds like everything went together nicely. Good luck on your build

 

[Stumpalama]

4 speed tranny in my 74 is bolted up to a 3 speed bellhousing, with stepped flywheel annd 3 finger clutch. 74 was the oddball year when they started to introduce the 4 speed tranny.

Maybe my bellhousing is a 4 speed? It is a possibility, I was under the impression that the bellhousing, flywheel, and clutch all had to match.

I could be wrong about this.

There is legend of a "transition year" and it was 1974...

 

[StaleAle]

Yes, I got one of the transition year H42 transmissions from Shmukster years ago. It had the gear needed to mate to the lower geared (2.31:1) 3-speed transfer case. My current 4 speed is bolted to a 4 speed bell housing but I retained the 3 speed stepped flywheel, three prong clutch pressure plate and 3 speed clutch master and release cylinders.

If you want to use a 3-speed t-case to get the lower gearing, Mark's Off Road sells the gear and bearing you will need to mate the 4 speed tranny to the 3 speed t-case.

The gearing for the three transmissions are as follows:

J30: 2.727 - 1.691 - 1.000
H42: 3.555 - 2.292 - 1.410 - 1.000
H41: 4.925 - 2.643 - 1.519 - 1.000
H41 "Unicorn": 5.299 - 2.830 - 1.634 - 1.000

 

[Stumpalama]

Never seen that last H41 gearing beforw.

 

[StaleAle]

Yeah, the "Unicorn" H41 is argued by some as being a myth. If I recall correctly, Mark told me he had seen only one H41 that appeared to him to have slightly lower gearing. Considering he has been handling these transmissions for a long time, I imagine this option was limited to specialized vehicles.

 

[Stumpalama]

Yeah, maybe there were mine trucks or some other "industrial use" trucks that snuck in.

 

[DustyFJ]

Thanks to rkymtnflyfshr I have a clutch to install in the 40. Got to do it on the cheap for now. Spent the day dropping the transmission with my girlfriend. It took far longer than I expected and was far messier. This week I'll install the new clutch.

My neighbor says I need a clutch alignment tool. Sounds like a stud to line up the clutch with the motor?? Does that sound right?? Where can I find that???

 

[rkymtnflyfisher]

Dammit, there is one laying around on my shelf! I should have passed that along with the clutch.

 

[DustyFJ]

Maybe I can ride the motorbike up to your place this week and borrow it.

 

[shmukster]

Maybe I can ride the motorbike up to your place this week and borrow it.

I have the alignment tool you need if you want to come up for it or can mail it in a priority box. No problem. I also have a brand new three finger clutch setup here not sure what you were going to put in your truck. You know where I live!

Four speed is one of the two best improvements you can make to an older cruiser. You've already hit the other one (disc brakes). If going from a three speed to a four speed you'll need a four speed bellhousing to allow the four speed to bolt up to it. Bolt pattern on the three speed tranny is different than a four speed, both bellhousings of course bolt right up to any F or 2F engine. You'll need a BH from a 40 or 55 to get the threaded holes on each side to which the rear motor mounts attach. Yes driveshaft lengths change, you can always use the longer part of a pair of four speed driveshafts mated with the stub ends of a three speed pair to get the right length and have the correct bolt patterns for the four speed flanges (each output of the transfer case) and the existing flanges on your front and rear axle. I just did this on a 73 FJ40.

Let me know if I can help with the alignment tool.