Lock outs, locking themselves problem.

^Sorry Lock outs not lockers: So I installed a grizzly locker on my front rear axle. To still keep the "tight turning" I installed overson double splined shafts and AVM lockouts so I could turn it off. NOW the axles keeps locking one side or the other on its own and it doesn't have to drive much to do so. I thought someone was playing tricks on me but then I unlocked them drove to work and saw it was locked again. It also isn't always the same side. I was warned that the shaft will have some horizontal play and slide in and out spline to spline but was told it wasn't going to be an issue. If I just keep driving with one side locking will that destroy my differential? I'm thinking I might just give up and sell the lock outs before I break something.

So you put your lockouts to the "free" position and after driving they are locked in? Sounds like something wrong with the lockouts.

Nothing really "wrong" with them. The only problem is that the shafts are 1-5/8" O.D. and the I.D. of the inner locking mechanism (it all turns WITH the dial knob) is... you guessed it: 1-5/8" - also !! Which means that if the shaft slides far enough out it may get stuck in there and next thing it does when it starts rotating, is drag the whole locking assembly out of its notch in the 4x2, un-locked position - to the 4x4 default position (= coil spring unloaded).

To confirm, remove the covers and you will see the marks left of the shafts rubbing inside that plastic part.

Solution: Just reduce the shaft diameter a tad, the last 15mm. Or slightly enlarge that plastic part of the hub (if you know how to disassemble it...) Or try adding a (soft) coil spring, to keep the shaft pushed IN. Or change brand of locking hubs...


G.

Is this reduce with a dremel or something I should have a lathe do. Im thinking a spring might be best, I'm just happy I didn't waste all this money.

Important update: I have sense bobbed the truck and when I removed the rear lockouts I found some disturbing stuff. Apparently the shafts had worked their way over to the passenger not allowing it to unlock and coming off the teeth of the driver side. Not before the tips could be ground off the shaft. Here are some pics of the damage. I have sense installed the front axle caps and they are snug with no more axle shaft play.

Ahh.. I see now, you had more than one problem there... First, the "auto-lock" issue which was probably solved somehow. But you also had this extreme shifting left to right, maybe over one inch!? I'm sure that those axle shafts would have worked OK with the stock differential parts and that - knowing the source- they are NOT too short!

I'm not familiar with this particular locker but it seems there is no element to act as a spacer in there, like the spider cross would be in the stock diff. So you already have about 7/8" of "extra" free-play at least. Now if the splines at the inner end were cut long enough the shafts could move inwards more than that, even past the center!?

This leaves me wondering what has actually changed now, that would keep those shafts from still shifting side to side?
I just don't buy that they won't... just because of a "snug" fit inside the hub flanges.

You will need some kind of spacer inside that locker, or simply go back to stock rear axle shafts and offer those splined shafts for folks who want to disconnect one side of the front-rear axle.

G.

Ill see how it works over the next couple of weeks. You are correct the shafts can push all the way through the diff, there is nothing separating them. When I talked to the manufactures tech he felt that they should have enough teeth to still work even with the extra play. From what I can tell it was just barely came off. I played around with it pushing them through and I feel their should be plenty of contact now that I switch. The lockouts were much deeper.

You should be able to tac weld a small Bolt or something of that nature to the inboard end of one of the shafts to keep this from happening again. Just something to take up the space. Be thankful that more wasn't totally destroyed.

That's a good idea. I have to flip the hubs still so when I do that Ill pull them out and weld a bolt in. It already has thread for a bolt to be screwed in, I assume from manufacturing. Ill find one that fits then weld it in place for good measure. Anyone object to this idea?

w3azel said:

That's a good idea. I have to flip the hubs still so when I do that Ill pull them out and weld a bolt in. It already has thread for a bolt to be screwed in, I assume from manufacturing. Ill find one that fits then weld it in place for good measure. Anyone object to this idea?

Click to expand...

Sounds like a plan. I would only weld a little bit on the shaft, maybe a stitch on two sides so you don't take out the temper of the shaft. I would also use a grade 8 bolt. Then with springs added to both sides (inside the lock-out hubs) you'll be golden !

This is interesting. I assumed the differential's spider gear had a shoulder or something to prevent the drive shaft from going in too far. I have a selectro lockout on my front most rear axle (drivers side) with a ouverson double splined shaft. I was always a little curious what holds the double splined axle shaft in place and prevents it from sliding side to side.
I can't picture the welded bolt idea though.... where would you mount that?

I would NOT weld anything to a shaft that certainly is alloy containing some carbon, not just mild steel!
It is just too risky that the weld would crack and that bolt ended up in between two gears...

I would investigate if there is something like a short cylinder - same diameter as the shafts, and maybe made of brass- that can be put in between the shafts as a spacer.
Why not ask the tech people who sell the "Grizzly" locker? They might have a solution...?


G.

gringeltaube said:

I would NOT weld anything to a shaft that certainly is alloy containing some carbon, not just mild steel!
It is just too risky that the weld would crack and that bolt ended up in between two gears...

I would investigate if there is something like a short cylinder - same diameter as the shafts, and maybe made of brass- that can be put in between the shafts as a spacer.
Why not ask the tech people who sell the "Grizzly" locker? They might have a solution...?


G.

Click to expand...

Your right Gerhard, but I figured he was going to do it anyway, that's why I told him to only weld a little bit, but no welding is best. On the differentials we use they have drilled out shafts that a rod goes into. In between the shafts then is a bronze block drilled out in the center that rides on the rod. It acts like a bushing which the shafts can push against. Most of our differentials are the planetary reduction type so the axles float. The other end (at the wheel) has a spring and tension adjuster. It is a hard system to keep in adjustment. In fact it has to be checked every 20,000 miles.

I'm going to pull one cap. Push the shaft all the way over and measure how much is still sticking out. The caps don't have teeth all the way to the end. So if it proves to not stick out far enough. Ill screw and tack a bolt on the end of each, at the cap ends. That way if the bolt snaps or falls out it will be trapped in the cap where it can't do any damage.

I have been self nominated to help you with a small grammar lesson for future posting purposes.

You posted:
"I have sense bobbed..." and "I have sense installed..."

What it should have been:
"I have since..."
Just trying to make sense of it all.

On another note, how do you like your grizzly locker? I assume you left it in the rear axle when you bobbed your deuce? Have you taken it off-road yet?

GRAMMAR! My old arch nemesis, we meet again.

Yes, I do still have the grizzly lockers front and rear. I have not taken the truck off-road yet because it is still mid build and I just had the new driveshaft made. I can say on the road the truck handles fine and I don't notice any issues with the rear locker. The short drive to the shop in front wheel drive on the other hand was extremely scary. I could feel the locker engage and the truck lurch. Not a fun experience. I can say I will not be driving around in 4x4 unless its on a really slick surface.

Take it slow and don't cause another problem

I'm planning to do a full rebuild of M35A2C front end this spring or early summer that includes all brake parts, seals, cleanup, re-grease, etc. I'm considering that Grizzly locker in addition to AVM hubs. I think the locker is lost effective up front and being able to unlock the front (once locker is installed) is essential for on-road. Hope to learn from what you find out. Did you check with JATonka or other experienced guy about the length of the drive axles? Also, when you installed the Grizzly lockers, did you check to see that they limited travel of the axle splines to match the side gears you took out?

Also, I wouldn't get in there and do any welding until you really understand what is happening and why. You could try dropping back to the stock drive axles in the front to confirm if they are contributing to the issues.

Thanks for sharing your experience!

w3azel said:

GRAMMAR! My old arch nemesis, we meet again.

Yes, I do still have the grizzly lockers front and rear. I have not taken the truck off-road yet because it is still mid build and I just had the new driveshaft made. I can say on the road the truck handles fine and I don't notice any issues with the rear locker. The short drive to the shop in front wheel drive on the other hand was extremely scary. I could feel the locker engage and the truck lurch. Not a fun experience. I can say I will not be driving around in 4x4 unless its on a really slick surface.

Click to expand...

brianp454 said:

....................You could try dropping back to the stock drive axles in the front to confirm if they are contributing to the issues.

Thanks for sharing your experience!

Click to expand...

Guess you should read post#5 (again)...
We are talking about the only one rear axle left after bobbing... (still) fitted with custom double-splined shafts.
Yes, the OP could go back to the stock, flanged axle shafts, anytime.


(That's what I would probably do... long before any other experiments that could end being costly...)


G.

Ahh, I see. Isn't the front rear axle after bobbing the front axle? Forgive me if understanding some of these posting are a little challenging at times...

gringeltaube said:

Guess you should read post#5 (again)...
We are talking about the only one rear axle left after bobbing... (still) fitted with custom double-splined shafts.
Yes, the OP could go back to the stock, flanged axle shafts, anytime.


(That's what I would probably do... long before any other experiments that could end being costly...)


G.

Click to expand...

Well today is a beautiful day and the wife might give me some time to tear into the axle and do some measuring. I don't have the original axle shafts but I suppose I could swap it out with the m36 that has stock axles. I have attached a "classified" pictures from early in the build to see what the truck had going on. Two axles have lockers and AVM lockouts. The front rear is in reference to where the axle was located prior to bobbing. Just to help explain why there were lockouts on it to begin with. I'm not going to weld anything inside the pumpkin and I'm going to see if I even have to add something on the outside ends to keep everything lined up. As far as the locker goes I still always liked having one in the rear more then the front. When engaged the truck will fight like **** to not turn. Especially if you keep the tandems. If you don't have power steering then I hope you have some serious hulk arms. That's what made the drive so scary in front wheel drive was because even with power steering the truck would fight and jerk if I didn't have the tires perfectly straight when I changed gears. The motivation I had to put lockers in was from my Grizzly atv. That thing never got stuck once you locked up everything. It would just plow forward like a beast. Even for a small ATV it was hard to get turning once the wheels were spinning. It had a tendency to just spin the front wheels and dig a rut that the rear would follow. The front tires don't grab and just pull you into a turn like you want unless on firm ground. Then when they do grab they fight to correct themselves straight forward.