All kinds of questions...

[TrebleHook]

Alright folks...this is why I joined...(to learn and to look a cool pics of CJs!!)

I just purchased a frame-off restored 1979 CJ7 with the AMC 258 i6 / 4.2l /T-4 /Dana 300 from a 1985.



Before I brought it home, the guy who did the restoration and PO (a very honest, skilled, and trustworthy Jeep lover, mechanic and machinist -- I saw his other projects and his shop-- total pro.) installed Wide-track axles with new one piece axles in the rear. Before bringing it home, I asked him to install a new polished aluminum valve cover and new seats front and rear. He did and the craftsmanship looks great and appears to be consistent with his general attention to detail.



If you can hang with me, there is more. When I first talked to the PO, he told me that it had a 3:10 "posi" rear end? I know that "posi" means posi-traction but I rarely hear it used with regards to Jeeps. I usually hear "lockers." The axle has a diff cover that looks like an AMC Dana 20 ...round and smooth. I presume its an AMC Dana 20 . The PO also told me that once the new axles installed it would be a 4:10 (maybe 4:11?) rear end.

When doing the wide-track conversion, the PO also moved the front shock mounts. They are now more vertical than the original 1979. He claimed that they are now in the same place as a 1985 and that basically, the entire Jeep is functionally a 1985.

So I am a bit confused.

1. What rear-end do I have, and what is the explanation for its gearing?

2. After driving it on the highway the 100 miles home (it was winding pretty good just to do 55-60) it has 3 leaks. One looks like its the rear pinion seal. One is dripping from the skid plate. The other is dripping from the rear of the oil pan. The valve cover looks really good. Ideas?

I am in the military and have easy access to the "Hobby Shop" on base where I can throw the Jeep on a lift for $4/hour and borrow basically any tool I need while there. I am interested in doing as much work as I can...without screwing something up.

Oh, by the way...I need this to be a daily driver.

Thanks in advance! I'm looking forward to the lessons....

Cheers!
Dylan

 

[CJ]

:ww: to our site!

Without seeing a pic of the rear cover - can't say if it is or is not an AMC20 (sounds like it is though)... Changing axles NEVER changes gear ratios.
To check the gearing, raise both rear wheels off of the ground, take note of the rear drive shaft (make a mark if needed), then rotate a wheel / tire one full rotation while counting the rotations of the drive shaft (NOTE: If both tires rotate the same way (you have posi / locker), if they do not you have an open differential - if you have an open differential then you have to make TWO rotations to calculate the gear ratio... NOW - It really can get fuzzy if you have an ARB or OX type locker -

We really need some pictures and some info on what you bought to tell you what you really have, it's not just a simple matter... :ww:

As for the leak? Usually a valve cover gasket, and pinion seal - I would be willing to bet the rear main (looking leak) is from the valve cover.

 

[CJ007]

1. What rear-end do I have, and what is the explanation for its gearing?
Probably a trac-loc AMC20 (you said round, 12 bolts?) Try this http://www.jeeptech.com/axle/amc20.html or there is another chart at Morris 4X4. If you want to know for sure and learn, open it up. If it has 3-5 little clutch plates stacked up on each side of the carrier its a trac lok. If there are just 4 gears without the little plates and the carrier is not real wide, its not. If its lunch box lokcer it will "tick tick" when you turn. Other lockers should say or post a pic.
2. After driving it on the highway the 100 miles home (it was winding pretty good just to do 55-60) Hence the reson for re gearing to 4.10 or higher, big tiresit has 3 leaks. One looks like its the rear pinion seal. prob easy, remove dshaft and yoke. Seal is usually less than $10 One is dripping from the skid plate. Need more detail, may be tcase seal, pretty common The other is dripping from the rear of the oil pan. The valve cover looks really good. May be running down the back, if not its prob the oil pan or rear main seal. they are both easy to change on this engine, the rear seal is accessed by dropping the oil pan

I am interested in doing as much work as I can...without screwing something up. These all use basic tools, you should be good. Just make sure you have a place that has parts on hand!

Oh, by the way...I need this to be a daily driver. Just make sure you have a place that has parts on hand!


Dylan

Good luck!!!

EDIT Those tires don't look to big...seems like it should be faster than that?