What do I have

K.WesleyII

I just added another parts Jeep to the herd.It is a 1980 CJ-7 304 auto.It has more rust than any 10 1979 gmc trucks combined.After this Jeep I will have to stop giving the bowtie boys a hard time about thier rust buckets.This Jeep is so rusty you need a tetnious shot to get within 5 feet of it.I would be afraid to drive it as it would fall apart even though I drove it on the trailer.I am going to use the transmission and transfer case in my 86 360 CJ-7.What my questions are is the gear ratios the same from a factory 6cyl. to a factory V8.If they are not the same which would you use in a summer river Jeep that I put a snowplow on for winter.This CJ is never abused and gas mileage is no concern.Also what transmission and transfercase does a 1980 CJ-7 v8 auto have.I know it is not a turbo 400 and a quadratrac.Thanks for the advice and the bandwidth,Keith

jeepsr4ever

Hey a rust bucket CJ....thats rare :?: You have a tf999 and a dana 300 probly 2:73 gears. They always went with the high gears when they used auto's in the cj's :smile:

K.WesleyII

Thanks for the reply.The exhaust manifolds were rusted clear thru and I have seen rusty jeeps but nothing like this one.Did they have gear options for the 86 CJ-7 with 6cyl. 5-speed or did you get a certain gear when you ordered a 5-speed.Which gears would be better for pushing snow.Thanks Keith

Penguin

If you don't drive it on the highway I would go for a T-18. Low gear with lots of power for pushing heavy snow.

Trailbst

From what I found the 258/304 got either 3.07 or 3.54 Didn't make any distinction for auto vs. manual. Have you tried one of the VIN decoders on line. They are usually pretty accurate. Tag on the axles. Usually the front one doesn't get messed with. Erik

K.WesleyII

Thanks for the info.I will try the decoders online.I have to stay with the auto trans because the wife has to drive home from the river and I don't have that much snow to move around in the winter(just two fiftyfoot driveways) here in S.E.Illinois.Thanks for the advice and bandwidth Keith

Mudrat

The BOM on my stock 85CJ-7 axles said 3.73. That was behind a 258/T-5/Dana 300. The VIN said it was made in Canada #-o Mudrat

eight

The only way to be sure of what you've got is to pull the diff covers off and find the markings, or count teeth. Stock gears have the ring and pinion tooth counts stamped on the edge of the ring gear. It'll be something like 38-14. Divide the first number by the second to get the ratio. Or if you can't find the markings, divide the number of teeth on the ring gear by the number of teeth on the pinion gear. Most jeeps of that time had 2.73 gears, except for the ones with the T5 overdrive transmission. That 86 with the 5 speed probably has 3.55 or 3.73 gears. Use whichever set of axles has the lower (numerically higher) gears. There's a good chance that the 86 has a d44 rear which is much better than the AMC20 in the 80 model.

Mudrat

eight wrote
Use whichever set of axles has the lower (numerically higher) gears. There's a good chance that the 86 has a d44 rear which is much better than the AMC20 in the 80 model.

Thanks 8, I put Moser 1-piece axles new bearings and stainless steel disk brakes in the rear. New u-joints and all new bearings in the front with new Warn locks.
Then, after I did all that before I even ran it out of the shop, I pulled them out and slid a set of Waggy tubes under it. Fronts a 44 the rear is the big tube AMC 20. Both have 4.56's - and the rear is a Detroit. :?

Mudrat

joey

FYI, The TF999 doesn't have a real good vent on it. Since you said that this was going to be a "river" jeep, I'm going to assume its going to see quite a bit of water. Search the web for writeups on relocating the vent tube from inside the bellhousing to the case. That will save you a rebuild from getting water inside the transmission.

jeepsr4ever

Welcome aboard Joey :t: Yup that is the downer of the 999,904,727 breather is behind the converter and you may have to pop a hole in the bellhousing casting and attach a breather or face certain tranny woes if you sink her