Diff rebuild - how to check tooth contact Ep.4
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- čas přidán 11. 01. 2018
- Join me & Tool Girl Sam for the final stage of the Differential check - tooth contact pattern.
Here we use a special yellow Engineers contact paint to show the contact between the pinion & crown wheel teeth, an important aspect as incorrect contact between the teeth can cause premature wear, excessive noise & tooth failure (breakage).
I have also included information about how various contact pattern types can be interpreted and the adjustments that need to be made to improve the contact point.
Andy Mechanic - Auta a dopravní prostředky
Great bunch of vids very informative for someone who has never done a diff. Thumbs up.!!! Thanks.
I sure like the videos, Andy basic as it may be I love them. I hardly build diffs but like to see them from time to time so I don’t forget how things work.ASME
+oliver m Thanks Oliver, appreciate your feedback. Diff rebuilds are something that really highlights the diminishing knowledge base for most Mechanics these days, which is sad to see.
Great to know you enjoy the videos and find them interesting.
Cheers for now.
Andy
I can’t imagine the MB guys redoing my diff at the moment are going to go to all this high level of effort (under warranty) to get it just right. I see why they wanted MB to replace the whole diff under warranty than having to do all this work. Pity MB did not agree. 2 weeks later they are still waiting for shims to come from Germany....
I am just glad this new work will be under a new warranty, because I can imagine the apprentice assigned is gunna get this stuff wrong.
Older American automobiles do have removable Diffs and etc.
However, as you almost said setting up a diff correctly can be a bitch.
You have to keep testing and adjusting over and over.
You have to install the carrier with original shims and the 4 bolts lightly torqued. Then you can check tooth mesh and backlash. Re- shimming and checking backlash and tooth mesh might have to be done several times. This is assuming the pinion was not touched or has been setup properly first.
Been watching all kinda of diff set up videos and this series was by far the biggest help I have noticed some are using a pinon depth checker from the start would that help assure better tooth contact in the end ?
Btw also started watching your other videos all great work the tool girls are great but Sam is the best I'm sure by this point she's more capable in a shop than some guys I know 🤣
I am getting prepared to build a ford 7 and also a ford 7 1/4 " diffs. I know that its hard to go back and replace the inner bearing shim but would be nice to see that and how much shim change needed. I am guessing pinion need to go in deeper, thicker shim. This video was long time back but thanks. That changing the shim to get coreect patern is hard butbi want to get it right. Thanks for thw hands on video. Jacqueline
You can't get that yellow contact paint for love nor money in the UK, seems NZ and US have a monopoly on the stuff! lol
Seems like your holding the differential upside down and I thought the drive side was on the flat side. Also, I’m wondering if your differentials in your country is completely different than the US. Because here the drive side is convex, and the cold side is concave, and then your description with your pictures you have a completely opposite.
nice overview.
i see you left out the first pinion shim which is fine for an overview but something you need to do if pattern isn't right.
yellow or white diff paint often comes with the diff rebuild kits. but its hilarious that no one in NZ stocks it.
measuring carrier preload via the pinion is weird. potential for inaccuracies. maybe ok for backyarders but its easy enough to get or make the tool to torque the carrier adjusters. that torque setting is important for the strength of the diff, so its well worth doing. also better to use torque gauge on the pinion to measure rolling resistance rather than just break away resistance.
most shops won't do diff's simply because there is to many types, a lot of little tricks to know like checking its not warped to start with. its simply easier to send it to a specialist. most mechanics will diagnose the fault, send faulty part to specialist for repair. much easier, quicker than having to have the special tools and knowledge required.
+tweak e hi, thanks for your input here. You are right, there are different ways of checking preload and I used the method as stated in both the Suzuki and Nissan service manuals.
I did try to make it clear that you must use the method stated in the service manual or the specs given will not relate.
I did mention about the pinion positioning shim but didn't include changing it in the videos as changing it is a long and drawn out procedure.
I did include information at the end of the video covering what changes need to be made based on contact pattern, be it backlash adjustment or a shim change behind the pinion gear.
Thanks again for your input & yes, very few car workshops know how to set up a differential these days.
Cheers
Andy
i must have missed that as you started with the inner pinion bearing and shim already fitted.
yes it does pay to use the method the specs are for if you have no other choice. but some manufactures are known for diff failures or use over-engineered parts so poor diff building doesn't really matter.
sometimes pays to go find aftermarket specs for the diff and set it up better than factory.
its a tricky subject for a beginners guide, but its worth explaining what a good way to do it, ie what your actually measuring, which may be different to what the manufactures procedure.
just thinking on that, its probably well worth doing a video showing the different methods of adjustment.
easy enough with torque wrench to show break away and rolling torque. could even show the difference between lube and no lube and why nissan has a different spec for when the seal is in (what happens if its a different seal?). easy enough to make a carrier bearing adjuster for the torque wrench. why under spec is bad but over spec is not so bad or in fact good.
+tweak e Sounds like a good idea and will bring the Series to a good conclusion. I'll see what I can come up with over the next few weeks....getting very busy with work again now.
Many thanks for your input on this. It's great to see so many people contributing to the channel now.
Right, time for an ice cold cider :-)
i have enjoyed the set of videos . as it something i have not done before. very informative. will the same the same principle applies to setting the bevel drive on a shaft drive bike ?
+Simon Rawle yes, the principle will be just the same. Great to know you enjoyed the videos & many thanks for the feedback. Cheers Andy
So in this case you would move the pinion out. By how far?
Rebuilding diffs may come back. BMW run ball bearings in their small engined cars to save fuel. They do not last very long at all. You can buy bearings from the aftermarket..I suspect others will follow the trend where performance emissions and economy are now more important than long life.
I've never seen diff paint that wasn't yellow
We do solid axles cause they're stronger. And it's easy to service it on the car
I think you have mixed up your drive and coast sides of the ring gear. I am studying for my ASE cert and have learned that the steeper side (convex) is the drive side.
Kristoff Lutchman, it depends if it's a front or rear axle, sence the wheels turn in opposite direction corresponding to the snout of the diff housing
What's that part number again for the !taking paint please Andy?
Not all American diffs are one piece you do have independent rear suspension that are just like the one you have some are solid all the way to the hub but you can take the whole thing down and work on it. There are also some that are pieces that are detachable tubes that are between the hub and diff that cover the shafts for the wheels hubs.
+mcrande Ah, Thanks for that. I haven't worked on much American stuff. Just the odd Jeep.
Cheers Andy
Andy Mechanic yes Jeep's and most pickup trucks use solid axles I'm just a CZcams mechanic meaning I watch shows like yours and EricTheCarGuy and I learn allot. I don't work on nothing anymore bad back bad heart still do my own motorcycle maintenance.
+mcrande Hey, good to have you on board. I work for Yamaha New Zealand now, I provide Motorcycle Service Support to all our dealerships. Basically, if they can't fix it they call me!
Andy Mechanic I must say I have watched every video you have I just binge watched your videos this last week to cold outside to ride or do anything else. P.s. I miss Harley tried to see her on Instagram but couldn't find her.
Always the way having to go those lengths to get simple things. I find NZ is crap for things like this, Im forever ordering from overseas
I was expecting you to hit yourself in the face with that torque wrench lol
Haha! It wouldn't have been the first time either! Cheers Andy
Sam doesn't find this fascinating? I'm shocked