My experience with fitting HF electric lockers.

I recently purchased some HF lockers direct from HF and thought I would document my experience here.

I'm in the process of building up a green laner (see this thread ) and decided I wanted lockers. Having heard of some people having issues with air seals on the air lockers I decided to go with the electric version. I contacted HF through Alibaba and the purchasing process was pretty smooth. About a week and a half later two diffs turned up on my doorstep, one ET207 (8 bolt front) and one ET208(rear).
 

They were well packed and the boxes were undamaged. On opening the packages it's pretty obvious they are Eaton locker clones. They even directly copied the Eaton manual. Overall quality seems not great but usable. Most of the internals are moulded powder metal. I have seen a few people complaining about the use of powder metal parts but the original planet and sun gears in a Suzuki diff are also powder metal, although the moulding quality is better in the Suzuki parts. The switches supplied with the diffs aren't compatible with any of the switch holes in the Jimny so you either have to cut new holes somewhere or find different switches.

   

 



 

On the 208 the locking plate that stops the solenoid from rotating sits rather high and doesn't catch the locating pin on the solenoid. It can be made to fit with a bit of judicious grinding and filing but in the end I made a new one. Apart from that the installation was pretty straight forward. Just don't do what I did and try to install the ring gear after installing the bearings. You have to remove the solenoid to fit the ring gear and it won't fit past the bearing. The manual clearly states this so I have no one to blame but myself.

 

Next came the front ET207 and that's where things started going down hill. I started bolting up the bearing caps and the diff locked up solid. After a bit of investigation I worked out that the pinion was hitting the body of the diff.  To figure out exactly where it was fouling I bolted the bearing caps on very lightly and rotated the diff. These are the witness marks left by the pinion.

 

Luckily I have a pretty well equipped workshop so I could modify the diff. It took about 6 tries of disassembling the diff, machining a bit off, refitting, finding where else binds then repeating. I hope I didn't damage the bearing taking it off and pressing it back on that many times.
For future reference I had to machine 1mm off the diameter of the body and grind 0.5mm off of each of the pinion pins. The ramp ring also needed 1mm off most of it's diameter. This allows a clearance of about 0.2mm between the diff carrier and the pinion.
Machining the ramp ring needed some creative fixturing...

 

Here's the final result.

 

At least the solenoid locating bracket is a good fit on this one.

I am in the process of contacting HF about this. It will be interesting to see what they have to say. As they are at the moment I'd definitely not recommend purchasing an ET207 locker unless you have access to a decent sized lathe and are willing to spend a lot of time messing around. The rear locker appears to be worth the money. I'll report back if I have any issues with them in use.



 

I have seen marks like that before. I fitted an ARB locking diff to the back axle of a LC 70 series. I noticed that the clearance between the diff. carrier and the pinion was on the limit. From memory it was about 0.040" (old money). ARB recommended grinding the tips of the pinion to increase this gap but the new owner was happy to accept it as it was. Bearing in mind that the owner was a rough driver i.e. lots of power and drop the clutch I was still surprised that a noise developed in the diff. and inspection showed gauge marks similar to yours. Also, but not necessarily relevant was the number of teeth on the crown wheel that showed signs of cracking.
My point is, has HF advised you as to clearance between diff carrier and pinion?

Roger

I'm amazed you got marking on the carrier with 0.040" clearance. That's about 1mm. My 0.2mm (0.008") clearance seems far too small then. When I first installed the carrier I had about -0.3mm (-0.012")

HF haven't got back to me yet but I only contacted them a few hours ago. They didn't have any clearance in their documentation.

It amazed me as well but that lad had no idea on how to drive smoothly. To him, if he wanted to get up a hill with ruts in the way it was flat out and launch the motor. He just didn't understand smooth and finesse. And this was a Toyota diff.. he was bending.
Best of luck with the fitting.

Roger

I tend more towards picking my line and control rather than boot it and pray so maybe mine will stay together. Pity there's not enough room to get an endoscope in the filler plug to take a look after a few miles. I may be able to peek through the drain plug though.

You will probably hear it, he did and he had little noise sympathy

What he twisted was the mountings for the diff. carrier. As you said, picking your line plus careful use of power - you have petrol, he had diesel - could make all the difference.

Roger

With 2 tenths of clearance I'd be more concerned about thermal expansion being the issue more than torque causing movement. Ok its not going to get as warm as the rear as it's not in a constant work condition but it will still get warm eventually.

Also what is the crown wheel contact patch like, could it be a pinion depthing issue?

As the housing will be heated by the hot oil inside the diff, the heat expansion will mostly be the same on housing and gears. Could be a problem when going thru a stream or driving in cold and wet weather. Easily calculated though, I can check when I get back to work.

Small gaps between rotating parts will also increase temperature and in worst cases make the oil foam and deteriorate.

I wonder if the 10 bolt front will have the same issues? Owners of older Jimnys may be better off buying that and sourcing a 10 bolt third member.
Anyway, I hope it all works out for you. A front locker is a great thing to have. Great traction without the loss of agility.

Another point comes to mind. Our cousins across the pond do not like the collapsible spacer on the pinion shaft and neither do I. The reasoning is that if the tube will collapse to give you the degree of pre-load required, then it can easily collapse a bit more and induce bending in the shaft and that could be the answer. So I bought a solid spacer and fitted it into the back axle of my LC. Now I hadn't had a problem before and the mod. didn't give me one after I fitted it as there was sufficient clearance but on the diff. in question with an obvious problem, it is something to think about.

Roger

wrote:

Also what is the crown wheel contact patch like, could it be a pinion depthing issue?
 

I have to admit I didn't check. I didn't touch the pinion and I doubt if Suzuki got it wrong originally. I'm pretty confident it's never been taken apart before.

I left the clearance as tight as it is because under load the pinion should be pushing the crown wheel away so if anything the clearance should increase. Oh well, the only way to find out is to run it for a while and see what happens.

I wonder if the 10 bolt front will have the same issues? Owners of older Jimnys may be better off buying that and sourcing a 10 bolt third member.

To be honest, looking back that's what I should have done. The 8 bolt doesn't fill me full of confidence. The bolt sticking through the side of the housing to control the ring gear flex really doesn't give me a warm and fuzzy feeling. By the way, does anyone know the correct adjustment of that bolt? I just left it alone in the hope that the clearance was already correct. I couldn't find any reference to it in the online manual.

As far as I know the 10 bolt is basically the same as the rear just with smaller splines so clearance should not be an issue.