CJ tub swap help

greengene · 12-22-2008, 02:41 PM

I am about to embark on a major project and I am trying to get prepared. I have a complete 1977 cj7 that I am going to morph with a 1985 cj7. I am using the tub and frame and axles from the 85. I am planning on buying new wiring harness and body mounts. I know there where alot of changes between these years but I wonder if some things are compatible like steering columns heating components ect. So can I use everything on my 77 with the exception of the things I plan on swapping?

**jeepskate** · 12-22-2008, 07:34 PM

IIRC the heater setup will be the only non-swappable item from the '77 (wouldn't swap it even if you could reasonably do it...use the '85 setup with a Blazer heater motor...common upgrade/retro-fit that's been documented on the 'net for at least a decade so you should have no problem finding the info). Beyond that, obviously the trans & t-case offerings were different and therefore the skid plates/crossmembers are different and not directly swappable.

fastas69 · 12-22-2008, 07:39 PM

Im getting ready to do the same thing. put a 78 CJ7 tub on a 83 CJ7 I just picked up a rust free 7 tub today for $150

dirt4900 · 12-23-2008, 03:31 AM

Quote:

Originally Posted by fastas69

Im getting ready to do the same thing. put a 78 CJ7 tub on a 83 CJ7 I just picked up a rust free 7 tub today for $150

bastard

- i cant find a tub for under $500 anywhere even close to me

**certifiablejeep** · 12-23-2008, 06:17 AM

Quote:

Originally Posted by greengene

I am about to embark on a major project and I am trying to get prepared. I have a complete 1977 cj7 that I am going to morph with a 1985 cj7. I am using the tub and frame and axles from the 85. I am planning on buying new wiring harness and body mounts. I know there where alot of changes between these years but I wonder if some things are compatible like steering columns heating components ect. So can I use everything on my 77 with the exception of the things I plan on swapping?

Maybe I am reading this wrong, but what excactly is morphing onto the 85 from the 77? Drivetrain? Because the tub/frame/axles make up a lot of the Jeep. Sheet metal going over? Dash?

One difference is the NT vs WT axles that are on the 77 vs. the 85, but you are going with the WT from the 85 so that is good, wider, so more stable.

The heater is different, as would be the roll bar I think... not sure if the 77 is just on the rear rails or if it goes down to the floor, can't remember. Hard doors would be different as well, depending on if you had them for one vs. the other.

One thing to note, I know it has been done before and you can search on it... you could take the NT setup from the knuckles out if they are discs and that way you would have the 6 bolt hubs vs. the 5 for the Wide Track axles. Just a thought.

Also, your transfer cases would be different... D300 in the 85... might want to use that, you didn't say much about the drivetrains, so it is a bit hard to go on here.

As for the steering columns, if you have a tilt in the 85, I would go with that... Also, PS/PB stuff from the 85 if the 77 didn't have it.

cb

fastas69 · 12-23-2008, 08:38 AM

Quote:

Originally Posted by certifiablejeep

The heater is different, as would be the roll bar I think... not sure if the 77 is just on the rear rails or if it goes down to the floor, can't remember. Hard doors would be different as well, depending on if you had them for one vs. the other.cb

Youre right about the roll bar it just sits up on top of the wheel wells, also the door strikers from the newer tub will have to be moved to the older one.

**only in a jeep cj** · 12-23-2008, 08:55 AM

There is so many large and small differences between the pre 82 and post 82 CJs that I would use as much of the 85 stuff as I could. Differences in axle width, drivetrain components, dash (speaker holes), roll bar, door style and striker post, tail lights, etc, etc.....I would only use the 304 from the 77 if you have one. Steering column should swap over....the 85 dash will give you two front speakers. Use the 85's Dana 300 if you have it too.

fastas69 · 12-23-2008, 02:26 PM

Heres one for you guys, the wiring harness inside the tub in the 78 is in mint condition and the one in my 83 is all hacked up. The only problem is the guy I bought the tub off of cut all the wires under the hood

So can I just put the 83 engine harness on the firewall of the 78 tub?

**only in a jeep cj** · 12-23-2008, 10:47 PM

Yeah, I think so. The engine harness needs to match the engine type and year span (if all your stuff is there and works). For 82 on, it would be the stepper motor on the carb, pulse air or air pump, Under dash computer, so on. Under the dash for the gauges and such, I think its the same and should plug and play.....maybe the heater wiring difference for 76 and 77.

**certifiablejeep** · 12-24-2008, 05:07 AM

I think there are a few differences.
Something like 2 speed and 3 speed heater motors?
Also, wiper switch... one has delay maybe and one doesn't... I can't remember on the years with delay and without.

Speaker differences in the dash, but that should affect the wiring harness persey, unless you want to tuck it in there all nice and neat.

With what was said on the computer, it depends on how you plan on having your setup... which carb, FI, etc. you plan on using. You can nutter it to get by the computer setup, just depends I guess on how your setup is going to be. I would say the first thing is just see if the part that goes into the firewall lines up with the part that goes into the engine bay from the ones you want to use and the wire colors are similar and the sockets plug together. Once that is OK, I think you can manage the rest. I say this because you want to know if it they are 2 stock setups in terms of wiring or if they were replaced at some point with an aftermarket setup.

cb

fastas69 · 12-24-2008, 07:53 AM

I thought about putting in a whole new harness, I have a new universal 10 circuit harness that I bought for a race car project. But I might just see how this engine harness pans out.

greengene · 02-09-2009, 10:17 AM

I just ordered a new gas tank and I come to find out there is a big difference between the two years. The 77 has a huge fill hole, so because I ordered the newer style I need a new filler neck with the smaller whole. If anyone has one laying around I would love to buy it. I also need a new tank skid plate mine is about gone.

greengene · 03-09-2009, 02:55 PM

Also I come to find out the doors are different too. After 1981 they changed. I have half doors that won't fit.