willysmjeeps.com

While working on the restoration of my 1953 M38a1, I am agonizing over whether to install a Warn overdrive. I am trying to keep the jeep reasonably authentic but the idea of moderately increasing the ground speed is very appealing. Before the restoration top speed was only about 35 or 40 mph, which can make a long ride, even within a 10-20 mile trip.

I am thinking of installing a custom shift linkage via the PTO cover on the floor of the tub, to eliminate any permanent modification.

Any opinions on whether the additional 7-10 mph ground speed is worth the expense and emergency brake modifications?

Have you considered obtaining a "second" trans cover that can be modified to accommodate the O/D shift lever? I think this would be a lot less work / cost effective as your orig cover is unhindered and stored with the assurance that the intended O/D shifting actuation will work properly.

I see early CJ5 covers on epay that avg. appx. $20 + shipping.
Lot less guilt cutting up one of these to fit an O/D.

I have an overdrive in my M170, and I love it.

The parking brake cable bracket on the M170 is different from M38 and M38A1 so I needed to make a new bracket for that, but the remainder was just trimming an old CJ5 cover...

Over here gasoline is $8.00 per gallon. You KNOW I need that overdrive. For a good look at the PTO-hole option, look at what ARTIFICER did on the G503 site. I've had a Warn OD in my 1952 M38A1 for 35+ years. In the last year it started popping out of OD (worn bearings in the TC, they say) so I put a heavy spring on the linkage underneath to keep it in OD all of the time. I miss being able to split gears, but not that much. If I had to do it again, I wouldn't put in the linkage at all. If I went rock-climbing, I would slide under the jeep and move the spring from pulling it into OD to pulling it into direct. OD's now come in 25% and 30%. I have the 25% and think that it is just great. "Herm The Overdrive Guy" is THE source for products, service and information. Enjoy!
David

First of all that 35 to 40 MPH is indicative of a sick M38A1. I've owned and driven several and I use one for a daily driver in Rapid City SD from Black Hawk to Ellsworth AFB on I94 and I cruised between 55 and 60 with the stock jeep. Had I been able to acquire a Warn overdrive back then I would have installed it. Not to go faster, but to lower cruise RPM from max to about 85% and save on gas.

Since you are in Idaho you will love the overdrive.