warn OD unit for Dana 18/20

[Joe J-Truck]

I heard of an old warn bolt-on overdrive unit for jeep Dana 18 or 20 t-case. Produced by Warn. I'd like to know more about these if anybody has any info.

[porkchop]

I will tell you what I know, which is very little. The overdrive will only work with the D18. It bolts directly behind the tranny. Since the D18 is right/right drop the overdrive will bolt to it. Warn stop making them awhile ago and sold the plans to Saturn (not the car company). They are really expensive!!! They can run from $800 used to $1200 new. I would love to get my hands on one since I am running a D18.

Here is a little write up from warn:
One of the most clever inventions to come out for the Jeep was the Warn dual-range overdrive. It is essentially a torque-splitter with a 25% overdrive and direct drive. The units are strong and add better highway driveability to Jeeps equipped with the Model 18 transfer case.

If you want to see a picture of one here it is:
Overdrive

I don't know if this helped you out at all but this is what I know.

[Dean]

Here's alittle more info. Warn ODs come in basicly 3 flavors, 33-26, 33-V6, 33-29, and 33-14. OK so 4 flavors. The differences were due to the input gear tooth count and splines. I have one kicking around along with a few spare parts and half the dohicky kit that allows you to bolt a PTO to the OD.
Make me an offer, the one I have is a 33-V6.

From what little first hand knowledge I have, Don't buy one if you have a 6 cylinder or bigger engine!!! I have seen 3 dead ones and even the one I have has a chipped tooth. They don't seem to like torque. Mostly street driven would be OK.

If you want more info about these things you might try Advanced Adaptors as they make and sell the Saturn OD (parts interchange with Warn). But based on the prices for adaptors they must use aluminum plated gold to make things from (or I'm a cheap SOB).

Dean.
YMMV, I was saving my warn OD for my stock 1945 CJ2a but the gears are different tooth count.

[porkchop]

What is the tooth count on the one you have? If it will match my D18 I am interested. It all depends on the tooth count and the price. Let me know so I can research it.

[Dean]

I need to dig all the parts up, I've had this thing for about 10 years. So far I have found the PTO adaptor, the shifter, the back major assembly and the input shaft. I still need to find the front major assembly. From what I can remember it is 29 tooth gear. the input is 6 spline... So you would need a 29 tooth, 6 spline Dana 18 to use this one. I have a spare 29 tooth gear for it somewhere.

PC, 1 other person is interested in it so far, let me find the rest of it and evaluate my needs (cash or parts). Price wise I won't rape anyone over it.

Later, Dean.

[porkchop]

Cool, I will be waiting to hear from you.

[jeepbob]

While the D18 in the D20 case is the strongest of te D18's, it is still a marginal t/case running a v8 in a full size rig. Adding the overdrive will make it even weaker, so I would be careful about adding the OD with big tires and off roading it. The OD is cool and if it wasn't for strength problems I would convert my D20 to a D18 and add the OD.

[Alaskaman]

I've had a Warn OD in a CJ3a for 20+ years. They are great, but have a poor lube system, its a stamped tray that catches gear lube thats slung around by the gears and gravity feeds into the OD unit. If the transfer case is leaky (standard feature on the old T18's) you have to watch the level closely, 'cause using the OD when the gear lube is low is terminal for the planetary gears. I learned that lesson early and well.

[Joe J-Truck]

Thanks for all the info, now that I now more about it, I know that I'd probably blow it up if I owned one.