Setting up bearing preload on a Dino differential.

Without the factory tools, how do you set up the preload on Dino differential carrier bearings? This, is not a check-up of the existing ones, but due to the very sad condition of everything, the bearings need replacing.

Thank you, Alberto

 

Clay, am clear of that all bearings are made under very close tolerance requirements. Yet, I believe that shims will not always remain the same, whenever you perform a bearing change, as there are infinitesimal dimensional differences. Do you mean that I should check the pinion preload without the guts of the transmission? Because if that is the case, it would add additional drag on the crown wheel. On a true ring and pinion installation things are very different, as you have set the preload on the pinion bearings with the nut in front of the pinion. In the Dino, it is a different setup as the pinion is just another helical gear is that meshes with the crown wheel. As you can see it is not quite so simple.
Regards, Alberto

 

Nickrry, I would love to see a photo of your rig fashioned from kitchen components. The shims are available from a variety of sources in a variety of sizes. I don't think that that is really the problem. If you have invented a better mousetrap, then by all means, I am extremely interested. Thank you.
Regards, Alberto

 

Nick,
Rube Goldberg, eat your heart out...
Great stuff.

Questions:
1. as per photos, I have a different setup, as you have a later E. transmission.
2. I am assuming, or while doing this adjustment, the transmission is full of it's internals.
3. Do you have to block one of the flanges, to prevent it from turning.
4. As I have adjustability on both output shaft bearings, I am not very clear how to proceed as the manual states that you require some other accoutrements to perform the adjustments. I am perfectly clear about the plywood wheel and the 7 pound weight, it is more about the smaller details. another point that comes to mind, is the blocking differential and its internal condition. Does that have any bearing, no pun intended, on the end results?
Thank you.
Regards, Alberto
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Nick, I think you have done real well. Both transmissions are the same differential wise, and the ability to preloading them. The only real significant difference is that on yours, on one side there are no shims to set the preload as you cannot access it, unless it is apart, and even then, there are no shim provisions. Only on the other side, you have the flange with the large disk that acts as a shim with the eight holes, and is the only one that is adjustable, and that you set at the 1.3mm.mark that you mention.
To reach the proper spec, did you have to modify the existing shim, or...?

On mine, both sides have shims, and just replacing the bearings and rotating it with a fish scale, it is fairly spot on at 4lbs. resistance with the original shims that came with it and not altering specs. It is just that I want to be really certain before buttoning things up.


Now, I've got that under control as far as the similarities or differences go. The question remains, as you're putting the 7 pounds on the pulley,
DO YOU BLOCK the other output flange?


My assumption, is that if you don't, the "differential" effect allows only the flange to rotate but not the crownwheel.
The other point, that I think is really worthwhile looking into, is doing this operation with an empty transmission, as there probably is added drag when fully built up.

It would be interesting to know the diameter of the plywood pulley, as there most likely is a multiplication factor involved with it, and the weight applied.

Thank you.

Regards Alberto

 

You are absolutely right David, we are mostly concerned on stting up the correct bearing preload.

Regards, Alberto

 

Nick, if I don't block the other flange, the crownwheel will not move and the other flange spins in reverse direction. All that is happening is the inside of the diifferential moving, and as it has slip in it, the crownwheel will not move. The plates are not worn, I checked, and the 40% lock that it has only comes to play as you drive, as both wheels are moving forward in unison. On the assembly manual it looks as if the tool that goes on the other flange and serves a purpose of blocking, albeit in a more elegant manner as it is a factory tool, and all I have is bailing wire that I tie to an appropriate location to prevent that flange to turn. I can also rotate both flanges forwards or backwards with both hands and then the crown wheel will turn. The only way to avoid a slipping situation, would be to have a fully locked differential, and that, still has no bearing whatsoever on the preload of the bearings because all you really want to achieve is to get that crownwheel to spin as you're adding the famous 7 pound weight.

What's kind of spooky, and I am speaking in concern for your box, is that you loaded it with 7 pounds and the other gears, adding more drag to it, as you did the operation with a fully assembled transmission. I hope I'm wrong on this issue otherwise it would imply that your bearings are less loaded than they should be as the crownwheel had to drag whatever else it was dragging and thus justifying the 7lbs.

I am not an engineer either, I just want to want to get it right, as I dislike unbuttoning things, and it has been a bit like that...


I am surprised no one from the 308-328 crowd has said anything about this operation, as the setup is pretty much the same, it is bearing preload, period. I am going to continue on my experimentation and will let you know.

Regards, Alberto

 

Nick, I am glad that I could be of help, if that is what it is that I'm doing. I think you are in the proper course, but something was amiss.
If you are in the UK, you might possibly give a ring to Colin, at Superformance, mention this issue to him, also involving me, and ask him if he is able through Ron, the in house guru, to get some good advice as on how to proceed. Colin is a really nice guy, I met with him last time I was in the neighborhood, and I'm sure that if he can, he will help us.

I know a fellow here, that set up my ring and pinion in a Ford F-150 truck without special tools and it is still perfect after years of hard use. He's more experience than special tools...I will ask him, see what he says.

Good luck on the disassembly and let me know your progress.

Regards, Alberto

 

Thank you David, it seems like we are finally going somewhere and it will work.

Nick, stick around...soon enough I'll have good news.

Kind regards, Alberto