Here is a picture of the difference I was talking about. The cap on the J20 is about 3.5" wide, the CJ's and other FSJ are only about 3". Most of the time the chain stores will give you the smaller one.
i have been looking at boxes to do the conversion on my cj and every box i come across measures 3 7/8". i went to my WD supplier for my work and checked out and measured 18 gear boxes for jeeps, chevys, buicks etc, you name it and they all measured 3 7/8". i have yet to find one that is small like the one in the picture.
so your pic of the large and small gear box has me wondering.
and so everyone knows, every saginaw gear box will bolt into any vehicle (that uses saginaw box) as long as
1.the input shaft splines are correct
2.the fittings are the corect style (flare or o-ring)
3.check if you need 3 or 4 mounting bolt holes
all three of these boxes had a 3/4 30 spline input shaft on them
the pitman arm shaft is the same size and spline count on every power box i checked.
So is there another way to id a J-20 box? i have bought 3 boxes in the last 2 days and honestly i cant see any major external differences between
the 78 j-20 box had flare fittings and had the nipple on the input shaft
the 85 j-20 box had o-ring fitting and the nipple on the input shaft
the 90 cherokee/wagoneer box o-ring fittings and no nipple on the input shaft
got one of the hoses. I've been looking at the belts on my engine and I'm trying to figure out how to route them once I add the p/s pump. I still have the smog pump on mine cause NV requires smog checks on registered vehicles newer than 68 or 69 (can't remember which but it doesn't matter anyway since my Jeep doesn't qualify) So if anyone has p/s and a smog pump can you please post a pic, so I can see how they mount up and how to run the belts. I've been through my chilton's and can't find anything about it.
God, guts, guns....without them we have no FREEDOM!
Big fan of these threads. I'm thinking of upgrading my leaking and sloppy CJ stock P/S box to a J20 box. Couple of questions... 1) will I need to upgrade the P/S pump as well? 2) can I still use the same drop pitman arm that I have mounted on the current box? 3) I'd also like to use a borgenson steering shaft, I get the feeling though that the input spline differential might foul me up here, correct?
1. Stock pump works
2. Pitman arm you have works
3. Call Borgeson and tell them the diameter and spline count of the steering box before ordering. They will get you the correct joint at the bottom of the shaft.
I am trying to use a J20 box to upgrade my 81 CJ7 from manual to P/s but the reman box I got from O'Reilly auto parts only had 3 mounting bolt holes. I think I will take it back and get one with 4. I am going through the trouble and spending the money on a aftermarket HD mounting bracket I may as well get all the bolt holes!
The J20/FSJ boxes mount exactly the same way but the spline count and diameter of the input shaft is different. A J20 box with power steering has the same spline count and dia. as a CJ box with manual steering (or so I've read). So a bell coupler from a power CJ column won't work on the J20 box.
So I can use my drop pitman arm I have for a manual box to fit correct.
What am I missing? The input shaft size and splines for a 83 CJ7 are .72" and 26 splines, which is exactly the same as an '83 J20. That is, however, according to autozone's website. Why would I need the coupler?
'83 CJ7. 258, T5, D300. D30, M20 1 pc. shafts
4" Skyjacker, 33x12.5.15 Nokian Vatiiva on wagon wheels.