Diff lock, front ot rear

davem201m38 · Post by **davem201m38** » Sat Apr 11, 2009 9:18 am

Hi all,
it's been a while since I was here last (family presures) sure I don't have to say more.
Anyway, nice to be back.
Now, I have a Lock Right Powertrax Automatic Positive-locking Diff kit to put in my M38.

My question is this, which diff should I put it in?
Since it isn't needed most of the time and I'd be in 4x4 when it was needed I'm tempted to put it in the front diff as I run old 50s free wheel hubs on the front so I can isolate all the moving parts up front and save wear.

Or is it best off in the rear diff?
What's your advice,
thanks,
Dave.

kenperkins · Post by **kenperkins** » Sat Apr 11, 2009 3:27 pm

their not interchangeable..either you have a locker for the 44 rear or you have one for the front 25.
you'd be better served with the locker in the rear

Post by **wesk** » Sun Apr 12, 2009 1:45 am

The problem with lockers is on the paved road. Any attempt at posi in the rear on icy roads results in the rear end trying to slide sideways. Any other time they are great. If driving on icy roads is not in your plans then the rear is the way to go.

One good reason not to put it in the front is the difficulty it creates in steering the beast especially off road in bumpy terrain.

davem201m38 · Post by **davem201m38** » Mon Apr 13, 2009 6:40 am

Thanks Wes,
I got this from Herm a few years ago and it's sat on a shelf ever since! can't remember now which one I bought front or rear and can't find anything on the box to tell me.
Pt Number 2110LR.RICH
Could LR be Locker Rear, guess I'll go and do some research. BUG Bare is winter ice is the problem.

The reason I was thinkiing of one in the front diff is with the free wheel hubs I can isolate it until I really need it.
Anyway this is minor thing at the moment as I have to replace the engine, and sort and oil leak on the tranny, and do the swivle pins, and straighten a shakel.
Hey Hoe,
Dave.

davem201m38 · Post by **davem201m38** » Mon Apr 13, 2009 7:17 am

Well I've managed to download a doc from the Reichmond gears site and it looks like Pt No, 2110 is for the 25 diff so this looks like a front kit, unless anybody knows better.............................

Post by **wesk** » Mon Apr 13, 2009 7:45 am

Dave,
In your case the front would be a good choice and would give you the best bite in an emergency with the weight biased to the front. Of course as I said above the steering will be a bear in tight turns.

davem201m38 · Post by **davem201m38** » Tue Apr 14, 2009 3:46 am

Thanks Wes, just so I've got this straight and I'm not misssing something really obvious (as I'm no expert)

The steering will be a very difficult, I understand that. But, that will be when the front axle is engauged, correct? When it's disengaged at the transfer box, and the free wheel hubs are set to free wheel then there will be no difference in the steering wieght? because the diff isn't turning.

On the rare occasions I need this lock I can live with the heavy steering.

One of my concerns is the increased stress on the steering box caused by the fight between me and the traction.

She steers fine (though seems to have a totally different feel to my MB) but it might show up any weakness in that little box with a suddden increase in wear or a failure.

Which brings me to my next question, but it's a job for the future, are there any rebuild kits availble for these steering boxes, I remember Ryan some years ago went through this I think?
Thanks,
Dave.

Post by **wesk** » Tue Apr 14, 2009 12:18 pm

David,
You are correct the extra steering effort will only be when the locker is in play. I do not believe it would cause a serious increase in gear box wear. Yes Midwest Military sells bearing kits. Keep in mind the USMC M38A1 contracts of the 60's all came with posi's both front and rear.

davem201m38 · Post by **davem201m38** » Mon May 04, 2009 8:44 am

I think I remember why I bought this now, I could use it in the rear of the M201 or the front of the M35.
Ah... I see only dimly through the mists of time.

whydahdvr · Post by **whydahdvr** » Tue May 05, 2009 5:40 am

OK. Maybe a stupid question but I have what seem to be the standard hubs from the manual pictures. They do not have locks on them. What can I expect driving off road with this? Or is there any difference? My understanding of the hub-lock is to allow the wheels to rotate freely but leave the front axle and front drive shaft from rotating. How beneficial would it be for me to add that to my jeep in the future? I intend to use it on local roads, paved and dirt, and within a 50 mile radius. Thanks.

Post by **wesk** » Tue May 05, 2009 7:41 am

Locking hubs serve two main functions. The reduce wear on the front axle and drive shaft and they save fuel. They do nothing to improve 4wd performance.

whydahdvr · Post by **whydahdvr** » Tue May 05, 2009 10:40 am

OK. That's what I thought. Sounds like if I plan to drive it a fair bit then adding those locking hubs is a good idea. Thanks!