700r4 in a 1990 Grand Wagoneer

Modified FSJ Tech Area
Post Reply

Topic author
Zoom1963
Posts: 4
Joined: Fri Dec 10, 2021 9:29 am

700r4 in a 1990 Grand Wagoneer

Post by Zoom1963 »

Was asked to put a 700r4 in a 1990 Grand Wagoneer. Has anyone on here actually accomplished this? Going to find a trans a transfer case from a 1/2 ton Chevy truck. What issues will I have? Will it clear gas tank?
User avatar

tgreese
Posts: 7118
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: 700r4 in a 1990 Grand Wagoneer

Post by tgreese »

Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
User avatar

dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: 700r4 in a 1990 Grand Wagoneer

Post by dodgerammit »

Zoom1963 wrote: Sat Jun 25, 2022 1:10 pm Was asked to put a 700r4 in a 1990 Grand Wagoneer. Has anyone on here actually accomplished this? Going to find a trans a transfer case from a 1/2 ton Chevy truck. What issues will I have? Will it clear gas tank?
Well, first is it won't bolt up without an adapter of some sort. I'd see what advance adapters has. edit: https://www.advanceadapters.com/amc-eng ... auto-trans You'll also need a special flexplate.

Make sure whatever case you get is driver's side drop. I know that pre 88 GMs (and a few through 90ish) were definitely passenger drop.

You'll need new driveshafts as the driveline geometry will be different.
I did a tom woods rear driveshaft once I swapped to a np 242 from the 229 and had no issues.

As for the fuel tank, the only way to know for sure is break out the tape measure and see before breaking out the tools.
If it is close, then I'd go ahead and plan on needing to change that just in case.

Are they wanting the OD aspect after an axle regear?

If they're just trying to save money by putting a different trans in instead of rebuilding the 727, they won't be.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

Topic author
Zoom1963
Posts: 4
Joined: Fri Dec 10, 2021 9:29 am

Re: 700r4 in a 1990 Grand Wagoneer

Post by Zoom1963 »

Have Novak adapter. Owner wants to keep 360. And likes the low first gear of the 700 plus the overdrive. I realize the cost will be more than any fuel savings. The gas tank might put this project over the top. That’s why I was trying to find someone who actually attempted it.
User avatar

Yeller
Posts: 1521
Joined: Thu Apr 01, 2021 7:54 am
Location: Rogers County Oklahoma

Re: 700r4 in a 1990 Grand Wagoneer

Post by Yeller »

I’ve not done one that vintage in a wagon but should be pretty straight forward. any of the transfer cases that have the front output on the correct side will work nicely. The IFS trucks have a much higher clocked output than the solid axle trucks so it should work just fine. Fuel tank might be an issue, if it is, it can be relocated to behind the axle with a blazer tank.
The bus I ride is so short it is a yellow Smart Car full of squirrels, monkeys and clowns.

1970 J2500 Resto Mod
https://www.fsjnetwork.com/forum/viewt ... 12&t=21395

1974 Bronco “Broncno”
https://classicbroncos.com/forums/threa ... st-3411909
User avatar

dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: 700r4 in a 1990 Grand Wagoneer

Post by dodgerammit »

Depending on the axle ratio, that OD may very well be useless. If stock, you have 2 ratios. 2.72 and 3.31. Very few have the 3.31 ratio.

FWIW, that is one of the reasons I kept the 727 after doing the LS swap in mine. With the 2.72, I don't need an OD gear. 45mph is about 1500-1600rpm Even at 70mph, I'm just above 2200rpm.

Having 2.72s I can understand the desire for a deeper 1st gear ratio in the transmission. The Lokar cable helps put the shift points where they actually should be. 20-25mph 1st to 2nd, then 40mph 2nd to 3rd. This helps greatly.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

Topic author
Zoom1963
Posts: 4
Joined: Fri Dec 10, 2021 9:29 am

Re: 700r4 in a 1990 Grand Wagoneer

Post by Zoom1963 »

Great info. Thanks. What about a rear gear change along with 700r4?
User avatar

dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: 700r4 in a 1990 Grand Wagoneer

Post by dodgerammit »

Zoom1963 wrote: Sun Jun 26, 2022 1:55 pm Great info. Thanks. What about a rear gear change along with 700r4?
You'll have to change both front and rear axle ratios or risk drivetrain damage if 4x4 is used.

Depending on ratio, there may be a carrier split (ie: if 2.72 going to something like 3.55 will require new carriers.

New bearings are a must.

If you've never done them before, they are not something you can do without specialty tools and lots of patience.

If you are comfortable with setting backlash, reading calipers, installing shims, etc you could probably get by for less than $1000 if not having to change carriers. If you have to change carriers or pay someone to do the job, then it'll get real expensive, real quick.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

will e
Posts: 5096
Joined: Sat Aug 18, 2012 8:21 am

Re: 700r4 in a 1990 Grand Wagoneer

Post by will e »

Use this gear ratio calculator:

http://www.grimmjeeper.com/gears.html

It's the best on the internet (and supported by one of our members). You can alter transmisson types (or set your own ratios), different transfer cases, adjust gear raitos and tire sizes. It shows useful off road information (crawl speed for example) but also shows different RPMS for given speeds in each transmission gear as well as speeds for provided RPMS for each transmission gear. It's very powerful for deciding what to do. It also has a side by side comparison feature.
81 Waggy 'WILL E' Retired
82 Cherokee WT - SOA/SF/high steer/Alcan springs/agr box/Borgeson steering shaft/AMC 401/performer/holley TA/HEI/BeCool/727/ALTAS (2.0/2.72/5.44)/D60 Snofighter(Yukon Zip,hubs,stubs,4.56)/14 Bolt (FF,BF shave, Discs, ARB,Artec Truss)/MTR 37X12.5/Corbeau XRS Baja & 5 point retractable harness/Hella Aux lights/tuffy console/killer32 sliders/Evil Twin bumpers, rack and roll cage/WARN 8000/TT Fabworks steering brace/dual batts/custom TC skid plate/ARB fridge
User avatar

dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: 700r4 in a 1990 Grand Wagoneer

Post by dodgerammit »

Dang it will e. lol. beat me to it.

BTW, if you find out the gear ratio and tire size, you can play around a bunch with what different ratios and transmissions will do as far as rpm in each gear with it. They have drop down menus for the most common transmissions and transfer cases.

That is what led my decision to keep my 727 and 2.72s for now.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD

Topic author
Zoom1963
Posts: 4
Joined: Fri Dec 10, 2021 9:29 am

Re: 700r4 in a 1990 Grand Wagoneer

Post by Zoom1963 »

Chart shows with 3.31 gear ratio, 31” tires, 700R4 with NP241 out of Chevy pickup. 1507 r.p.m. at 60 mph in 4th gear.
User avatar

dodgerammit
Posts: 1434
Joined: Wed Jan 11, 2017 11:20 pm
Location: Middle TN

Re: 700r4 in a 1990 Grand Wagoneer

Post by dodgerammit »

Zoom1963 wrote: Thu Jun 30, 2022 2:51 pm Chart shows with 3.31 gear ratio, 31” tires, 700R4 with NP241 out of Chevy pickup. 1507 r.p.m. at 60 mph in 4th gear.
Yeah, the OD probably will not be very usable with 31s and that ratio. You're gonna be lugging that motor below 60mph and 4th gear. Any grade and that motor will want 3rd gear, even at highway speeds. You want OD coming in about 50mph to realistically utilize it.
That would mean 4.11s. At the minimum, 3.73s.

FWIW, my tires are 235/75 15s (29s), which are the stock size. If I plug my numbers in beside your numbers, those 31" tires give you about the same results I get.

Not trying to discourage you, just give you an expectation of what will probably happen.
84 Grand Waggy-Radio Flyer (Garnet Red/3M Ebony Metallic woodgrain, with honey interior) AMC 360 :cry: 2004 4.8LS/Advance Adapter/727/242 D44/AMC20 Serehill tailgate and headlight harnesses :fsj: Ongoing thread-viewtopic.php?t=11897

92 Wrangler Islander 4.0/32RH/231 D30/D35 RHD
User avatar

jpswapmohn
Posts: 656
Joined: Sun Mar 02, 2014 6:08 pm
Location: CO

Re: 700r4 in a 1990 Grand Wagoneer

Post by jpswapmohn »

Not a direct answer, but I have a 4l60e behind the LT1 currently in my 88GW. I went to 4.10 gears at the time and the trans behaved very well. I was getting 17-19mpg regularly, but the LT1 is a different animal than the AMC 360.. I was running the stock NP229. I since changed to he NP242, but unless in 4WD, the transfer case doesn't play into the numbers.

When I swapped to J20 axles, I went 3.73 gears (seemed like a good idea at the time). The trans is currently inop and I didn't get enough miles on it to say how it behaves with those gears. It cruised fine. All calculations indicate it should be good for a daily driver.

I agree that with the OD, the axle gearing really needs to be higher than 3.31, which is what my GW had originally. The short time I drove it (a long time ago, so memory isn't great), the engine was too low in the RPM band in OD. It bounced back and forth between 3rd and 4th a lot. At cruising speed on the highway, it did fine on reasonable flat terrain. I was running 32" tires as well, which factors into the equation.

With 4.10 gears on 32's, I was just above 2000rpms at 70ish mph. I will say that low end torque in 1st was great with this set up.

I plan on 34" tires (not sure will fit with WT flares and 4" lift, but that's the plan..). Calculator says I should be at about 1800 rpms at 70mph. If I have to drop to 33" tires, I will be at 1860rpm. Should be good for my setup. Might have been a little better to go back to 4.10's.

The calculator, in case you haven't tried it, indicates that the 727 with 3.31 gears on 31" tires will tac at 2650 at 70mph.
Stock on 30" tires, 727, NP229, 2.72 gears puts you at 2250rpms at 70mph.
One day I will wake up and realize that my jeep is complete...one day, I just know it.
88Wag, LT1/4L60E/NP242, J20 axles, etc. http://imgbox.com/g/rNuIasKYrS
95YJ, STaK, D44's, SOA, ARB's, Bilstein 5150s, 35" KM2's
50 CJ3A
77 J-10 (sold)
Post Reply