Differential Build Tool Ideas
 

I would like to start this thread as a place to put ideas for differential building tools.

What have you used or adapted or made to do this job. I have attached a few of my own ideas and tools I made or had made in China.

Also if there is any interest in Chinese made tools I can design them and have them made, if there is significant interest.

The attached pictures show:

My differential stand with adapter plate I made to fit to a Ford 9" diff stand.

Pinion Depth setting tool

A mandrel for pressing pinion bearings on that I am having quoted right now. If anyone is interested in these let me know this week.

Modifications I have done to use an OTC 4534 bearing puller kit to remove the side bearings from a 126/107 210mm diff.

More will come as I get more into this, but I know there are other people here that can contribute to this thread.

What are you using for a case spreader?

Not so smart looking stuff (but)
 

Oooo that looks nice and shiny and professional

To be honest I don't like to put that kind of effort into special tools that will then clutter up my already full up workshop - I have a system of chuck 'em once done - for that reason I make things from wood where necessary. Wood can have a second use even if it is just to end up in the wood burning stove!

For my Volvo PV544 build I did, however, make a metal case spreader which could easily be adapted for Mercedes differentials =>

http://www.peachparts.com/shopforum/...1&d=1544974548


If folks here want the full set of pictures I took I can add them here too (but they can be found if you register and log in to the Volvo forum thread linked in my sig)



####


I'm of the opinion that the pinion and crown wheel measuring equipment is a bit of a luxury - I'm sure it can help - but in most situations you are fixing something that has already been "calculated". The only way to check for properly meshing cogs is to use engineers blue and look at the contact patterns...


...the trick to getting that right is to apply some braking force to the crown wheel to make sure the pinion and crown wheel are properly loaded.


For a Series Land Rover differential I resorted to wood and some spare half shafts =>


https://www.landyzone.co.uk/attachme...ch-jpg.113033/


https://www.landyzone.co.uk/land-rover/1965-series-2a-station-wagon-in-holland.298002/page-23#post-3885354


All very Heath Robinson I know but I'm aiming for effect rather than posh special tools (!)

Not required for an MB 126/107 diff. Case is pre-loaded with the side caps.

Nice whatever gets the job done. The pinion setting tool I made has to be precision so I spent some time with that, and yes I made a box to store it. But I do expect to be doing this more than once. But the adapter plate to hold the diff was plasma cut from a 1/4" plate I got from Home Depot.

Pinion depth becomes important when transferring a used set of gear from one case to another, as I am doing right now. More important than the deviation printed on the gear set is the actual dimension the pinion was installed at in a car that ran quiet and well with the gear set you will be transplanting. Of course a pattern check is something you will also want to do. It also saves on repeated crush collar consumption.

If I were you I'd use an old crush washer as a temporary fix just to check the meshing of the gears with engineers blue - it is indeed doing the job twice but I get the feeling that the measurements are more or less a starting point.


Have you been having troubles finding the shims at a reasonable price?

Yes, having transferred parts from one to another on various models, keeping pinion shims with the housing works fine. Housings are machined but gears are ground making them more consistent. Even with taking gear variation in account, once things wear the pattern changes.

Another consideration. Gear sets in general are categorized as Hunting , Semi Hunting and Non Hunting. A Hunting gear always has the same drive tooth engaging on the same driven tooth. Semi has a repeating pattern and Non a pattern where each tooth eventually contacts another tooth.

If one takes apart a Hunting / Semi gear set and reclocks it, it might make noise / have variable backlash. I have not gone to the extent to mark or check what system gear sets I'm working on use.

Absolutely

I haven't been down that road yet but I have plenty of diff to scrounge from and a surface grinder.

I disagree with that. Pinions have markings on them showing the difference in the pinion height. Keeping the pinion shims with the housing will only work well if the pinion that came out of the housing has the same marking as the pinion that you are putting in. For example if the pinion removed from the housing has a 08 on it, meaning 0.08mm deviation from perfect, you cant expect that housing and shim set to work with a pinion marked -0.02. Better subtract a 0.1 shim thickness. your tolorance on this is +0.01mm - 0.02mm. That equals +.0004" -.0008". Pretty tight. Just for that reason, I'm using a Mitutoyo Digital indicator with 0.001mm resolution, and a Mitutoyo 2" standard calibration block acurate to about 0.000001mm.

However using the shims that came with the case and adjusting the stack as stated above is a really good thing to do it you cant do an out right measurement.

I think you have your hunting / non hunting backwards but the idea is correct. This is why you rarely see 3.00 or 4.00. The pinion usually has a prime number of teeth so that the pinion and ring will never be divisible by one another and the same sequencing of teeth take a long time to come into mesh. but eventually the same pattern does restart so clocking is not a consideration.

Clocking would be more of a consideration for a non-hunting mesh where the gear set will always see the same tooth contact.

But in either case if you have a measurable variation in backlash or gear pattern, its time to chuck the gear set.

My 1969 Mercury Cougar had a 3.0 diff.

If you're doing a lot of these differentials in the future I reckon you're gonna need a good source for shim material. The dealership costs are not in my opinion reasonable and a lot of the shims I have bought have not been the thickness I wanted - pain in the arse (especially as I don't have a controlled way to modify them

Yes, when going " by the book " however the gear variation is slight. In a shop I worked at, we would take internals from a older model and install them into a newer housing. Keeping the housings shim always worked.

From what I recall, the gears were not marked for variation or any paint marking was long gone by the time we took things apart.


Possible, I didn't do a complete fact check.

My EPC is down now so I cant check availability. About how much do these things cost. Is the problem that not all sizes are available. Or is nothing available.

McMaster Carr here in the states will custom make shim's of course you have to order them by the sheet meaning all sizes on the sheet will be the same. I will also have to check with them on what material is available. MB says these shims must be hardened. There are plenty of places that will custom make these but small quantities makes it difficult.

Perhaps if there are a couple of guys on this forum that would like to order shims in a select set of sizes we could justify a group buy. I suspect the interest would be low so if three guys were interested they would end up with 10 sizes with 5 of each size or something like that. Expensive but might be cheaper than MB.

How about the side cap shims, same problem?

It definitely would be a lot safer keeping the shims with the case over keeping the shims with the pinion as the case variation will be much more significant. But if you keep track of what was originally in the case and the new pinion that is going back into the case, you can up your chances of success. The pinions are laser etched see the + 08 in the picture.

All the shims I've come across so far have been seriously expensive. For the parts I've been trying to find a surprising number of options are still available in principle. I'm not sure how long they are going to be around though - the impression I get from Germany is that they are running down their stores inventory and are less and less likely to be restocking.



I've found the cost of shims has been similarly expensive for Volvos and for Land Rovers.