Hello, and upgrading a '76

[DANsCJ7]

This is my first post, but thanks for all the great advice y'all have handed out in this forum- I've learned a lot already. My son Dan and I are restoring a '76 CJ7 for him. As part of it we wanted to use his uncle's '86 CJ7 as a parts car, and take advantage of the wider axles, Dana 300 , and 5-speed. The '86 is no longer stock; a chevy 350 was adapted to the T-5 , I know, it's the weak T-5 , but it's free, and it's part of the family. The original tranny on the '76 is the bulletproof T-150 , the motor is the AMC 258 i6 / 4.2l I6. My question is, what is involved in this swap? I assume I will need an '86 flywheel, clutch, bellhousing, and tranny mount. The input shaft gear on the T-5 was torn up by the 350, so it will need to be replaced. I was planning to change to a 10 spline 23T shaft from the current 14 spline, to increase clutch choices. Any other items to be concerned about in adapting a '76 motor to an '86 drivetrain? Otherwise I was going to use a standard T-5 rebuild kit. Any thoughts on which rebuild kits are best quality? Allstategear.com has great prices- is it all junk? What other parts am I missing in this swap? In regard to the excellent Dana 300 , should I only replace seals/ gaskets, or do the whole rebuild? It has 150k miles. - Dave

 

[IOPort51]

Question:are the axle drops the same on the wide tracks as the originals??

 

[DANsCJ7]

Hmm, not sure what you're asking, due to my ignorance. I was under the impression that the wider track axles were easy to retrofit to the early CJs, so to keep the installation of the tranny and Dana 300 simple, I was going to put both axles, tranny, Dana 300 , and driveshafts right into the 76 jeep. As long as the frame is unchanged, shouldnt this work? I appreciate your help

 

[IOPort51]

is the differential housing on the same side on both front axles, drivers or passenger side? Is the rear diff pretty close to center on both?

ignorance is a temporary condition, I am sure you will get over it.

actually I guess I am questioning your swap combination. The Dana 300 is ,arguably, better than a Dana 20 Transfer Case but the T-5 really doesn't do it for me. If the axle drops are on the same side on both sets of axles I could see using them but to go to all that trouble and put a T-5 in front of them seems like a step backward.

these, as always, are just my opinion.

 

[DANsCJ7]

I give that the T-5 is weak. My brother-in-law chewed up a few when he put it behind the 350 sbc. I would like to rebuild it and see if I can make it last behind the AMC 258 i6 / 4.2l . If not, I'll invest in a beefy 5 speed or maybe change to automatic, TH350? maybe?.
I re to your questions, yes, all axle positions are identical betw cars, and shouldnt matter as all 86 parts are going to the 76, right?

 

[Saddle Tramp]

No change in flywheels or bell housing bolt patterns from one year to another for the AMC I6 motors. The thing about the 1986 CJ7s is that some of them come with a Dana 44 rear-end. To check which axle you have look at the differential. If the cover is round like a ball then it is an AMC20 . If it is an AMC20 check to see if it has the original 2 piece shafts or has been upgraded to solid axles. If a SBC has been living in the jeep they may be solid axles as the 2 piece axles most likely would not have survived, but then again they could have just the same. There will be a big nut on the hub of the 2 piece. All 1972 to 1986 CJs have a centered rear differential and a passenger side front. The wide track axles are bolt on compatible, just wider than your 1976. The other advantage to using the 1986 front axle is that it has disk brakes and the 1976 CJ did not but I’m not sure if the drum brake booster and the disk brake booster are the same thing so you may need to look into that.

Don’t waste any money on the T-5 . What Transmission you go with depends upon what you are looking for in the jeep; low geared trail rider or highway ponder/grocery getter for example. For low gear consider a T-18 but if not you may want a T-176 as it is Dana 300 ready. As you have a CJ7 and not a CJ5 you have the extra length needed for an adaptor to mate the T-18 and the Dana 300 . Your existing T-150 , the T-18 , and the T176s all use an 1-1/8”, 10 spline shaft.

 

[DANsCJ7]

Thx for the great advice. I do believe the previous owner of the 86 said he blew the rear end years ago and replaced it with a non-jeep unit that required shortening to match the fronts, so I doubt it's a Dana or Mac unit. Will have to research this further. Any advice on reputable tranny rebuild parts?