PDA

View Full Version : 4 Speed Swap With 3 Speed Clutch


Rzeppa
05-17-2006, 01:45 PM
I am trying to figure out what will be required for swapping an H42 into my 71. Reason is the need for an engine refresh, and "while I'm in there", since I already have the H42 sitting around. I hate to lose the column shift, but frankly, 1st in the J30 sucks, especially with 33s.

I know the traditional swap uses the 4 speed clutch and bellhousing. I know the 4 speed bellhousing is required, and I have one. But I checked my parts stash and all I have is 3 speed flywheels, and I test fitted a 4 speed pressure plate to a 3 speed flywheel and it doesn't fit, just a tad too large in outer diameter.

The 4 speed bellhousing *looks* like it is symetrical as far as release fork mounting, so it looks like the 3 speed fork and slave could be mounted on the 4 speed bellhousing, from the 3 speed side. I checked, and the mounting ear bolts from the 3 speed will fit the 4 speed bellhousing. A 3 speed friction plate fits just fine on the H42 input shaft.

Has anyone done this? Am I overlooking anything obvious? I know I'll need the transition gear for the t-case. I'll also need the stick shifter for the H42, the spring and the shifter fastening plate (anyone got one F/S?).

TIA,

FJBen
05-17-2006, 01:50 PM
I still have the H42 shifter and required items, also a have a used 4 speed clutch that I believe is in decent shape. I could take some pics tonight and get some measurements to tell you where it's at.

treerootCO
05-17-2006, 03:21 PM
If you are asking wether or not you can mount the slave cylinder on the passenger side like your 71 with a 4 speed bellhousing, then yes. It can be mounted on either side. The slave cylinder is the same from 7/70-8/74 it just changed sides. Everything should rotate around except possibly the bellhousing mount. I have around 10 or so 4 speed flywheels if you need one.

Rzeppa
05-18-2006, 03:21 PM
Thanks guys! I've gotten a number of replies from the LCML that say yes, no problem using 3 speed flywheel and clutch in a 4 speed housing, so that's the way I'll go. Ben, I could sure use that shifter, retainer and spring. Let me know how much you want for it.

Also, I have what appear to be a zillion 3 speed clutch inspection covers but haven't come across a 4 speed cover. Anyone have one? And last, "while I'm in there" (refreshing an engine for this project), I'd like to put on 2 row crank and fan pulleys for future P/S...anybody have any lying around?

TIA!

Rzeppa
06-01-2006, 10:51 AM
I still have the H42 shifter and required items, also a have a used 4 speed clutch that I believe is in decent shape. I could take some pics tonight and get some measurements to tell you where it's at.Hey Ben, are you planning on coming to the meeting next Wednesday? Hopefully I'll be ready for that shifter and bits real soon. Gotta have the rig ready for the Father's Day run. TIA!

FJBen
06-01-2006, 01:56 PM
Hey Ben, are you planning on coming to the meeting next Wednesday? Hopefully I'll be ready for that shifter and bits real soon. Gotta have the rig ready for the Father's Day run. TIA!


I won't be at the meeting :( But if someone is coming up to the Cleanup Run on Crystal Mountain this saturday from down there, I can bring the parts up there.

What all do ya need?

Rzeppa
06-01-2006, 03:49 PM
I won't be at the meeting :( But if someone is coming up to the Cleanup Run on Crystal Mountain this saturday from down there, I can bring the parts up there.

What all do ya need?I need the shifter itself, the spring, the seat for the top of the spring and the coller thingie that holds the shifter down. If you still have it, it looks like I'll need the dust cover for the bottom of the bellhousing. No idea how I ended up with a spare 4 speed bellhousing but no dust cover. Thanks!