Quaife ATB differential

G0bble wrote:
Ok that was useful - I haven't quiet finished reading the beginner textbook on drivetrains so please correct this non-engineer novice, if I am wrong - (and I am only going by all the Youtube videos I have seen so far).

1. Can a slight mm variation in dimensions/size of the new LSD (compared to Original) change the existing backlash settings for the Crown/Pinion when I fit it in?

2. How exactly do I adjust backlash when (No.29,30) are going be self-contained inside the LSD?

3. After I adjust the backlash do I need to readjust the preload on the Pinion using Shims (No.4)? (which ideally I would not have touched when removing the original diff)... Meaning should I go in armed with extra shims to add (if not remove) be safe? (On the side - is it right that the MG413 appears to use a fixed collar (No.3) and shims (no.4) for preload unlike the UK Jimnys that use crushed collar)?

4. If I need to adjust the Shims (No.4) on the Pinion - will I need to remove the propeller shaft and place the diff on a table to now adjust both preload and backlash in turns iteratively using a DTI Dial indicator and a fish scale (measure and repeat until the right values are attained)? Which means I need to find the right value ranges for the MG413 which will be different from the Jimny and Samurai... and then also only go after finding a fish scale (not a weight scale looks like)? Also it looks like there is a fitment with a string required to be bolted to the pinion flange on Suzukis before force can be measured accurately - which I need to check if the Garage is going to have... (not even sure if the MG413s need this or it was only for the UK Jimnys)

5. Like in the diagram - Do I open the LSD and place the "cap" on one side of the crown gear and bolt it into the other side through the threads in the Crown gear ( joining (No.23) and (No.21) in the diagram)?

6. Some videos I saw (and it makes sense) recommended replacing brand new bearings rather than reuse old ones. My car has done +80k kms already and I would rather replace the bearings (No. 25,26). What are your thought on this? If the answer to (Q.3) above is Yes then also replace (No.6)?

1) Yes, that is why its important to set the backlash up properly with the dial indicator.

2) Backlash is adjusted with the parts numbered 26 in the diagram. They screw into the side and apply preload to the bearings. screw one in and the other out by an equal amount to move the crown wheel in or out. Check the tooth match pattern with some gear marking paint between the ring and pinion gears.

3) You dont need to fiddle with the pinion shaft unless the bearings are damaged (unlikely). In the diagram the crush tube is part 3 and looks identical to the Jimny one.

4) As above, but re the scale - that is to measure how much force it takes to start the flange turning. In reality any scale could be used as long as you remember to measure everything before taking it apart, then get it to the same when refitting. Even if your not touching the pinion, it would be wise to check this before and after fitting the locker.

5) Not quite; parts 21 & 23 (and everything inside them) are completely replaced by the new locker. The crown wheel is kept from the old centre, but thats all. It will simply bolt onto the new locker without having to take the locker apart at all.

6) Optional, if the bearings are in good condition and can be removed from the old 21 & 23 parts then why replace them? It would be easier not having to remove them and only having to press on new ones to the new locker. I would still avoid changing the pinion bearing unless really necessary.

Martin's video about an airlocker install is pretty much exactly the same job, except with the extra complexity of the airline. It shows setting the backlash well:

I would suggest you find your nearest Maruti dealership and talk to the service manager about suitable workshops that he would recommend. It would be best if you did this face to face because it is normal practice - certainly in the UK - that the service manager will say "oh we can do that for you" when in reality they will farm it out to a local specialist and then add on a percentage to cover "costs and incidentals". The only people more unscrupulous than the motor trade are horse dealers! When you find a likely workshop, have a look inside, is it clean and tidy and and is the equipment neatly arranged. If not!!!!!

Roger

Roger

Hey Folks,
The parts arrived this week.
I am going to purchase a DTI guage to use in a local garage - I am looking at one with a measurement accuracy if 0.01mm and a range of 0-10mm. Will it suffice or do I need one with a larger measurement range like 0-25mm?

For the rest of the background - A.S.Cs have a policy of not doing custom modification work. All the garages I called chickened out as soon as I start talking about measuring and correcting backlash or checking gear contact pattern with some marker compound. They don't event want to discuss the money if its going to take extra time - they just chicken out - this includes the big names in sports and rally car modifications and tweaking.
So I plan to work with a local garage and while the mechanics do the heavy lifting I will just measure the backlash and ask them to correct it if it does not match the original.

mlines wrote: I used this one

Digital Dial Indicator 0.001mm/0.00005'' Neoteck DTI Dial Test Gauge Range 0-25.4mm/1'' Digital Probe Indicator Dial Test Indicators Electronic Indica

Digital Dial Indicator 0.001mm/0.00005'' Neoteck DTI Dial Test Gauge Range 0-25.4mm/1''

www.amazon.co.uk/gp/product/B076CZG6HX/r..._title?ie=UTF8&psc=1

Thanks Martin - Do we really need a .001mm guage or will a .01mm gauge do? Any idea what readings I can expect at default for the backlash?

Back lash will usually be between 0.15mm - 0.2mm, so you are aiming for 0.175mm but remember you need to take 3 separate measurements at 120 degree increments.
You also need to check the crown wheel runout. this is typically 0.1mm and again should be checked at 3 different positions.
Remember also that when you buy your dial gauge you will need a magnetic stand with it's various arms and clamps. Quit often you can buy them as complete kits. From experience, American tolerances regarding bearing fit are much tighter than Japanese equivalent, so be prepared to fit the taper roller inner races with a hydraulic press.
Take your time and ask lots of questions.

Roger

Roger Fairclough wrote: Back lash will usually be between 0.15mm - 0.2mm, so you are aiming for 0.175mm but remember you need to take 3 separate measurements at 120 degree increments.
You also need to check the crown wheel runout. this is typically 0.1mm and again should be checked at 3 different positions.
Remember also that when you buy your dial gauge you will need a magnetic stand with it's various arms and clamps. Quit often you can buy them as complete kits. From experience, American tolerances regarding bearing fit are much tighter than Japanese equivalent, so be prepared to fit the taper roller inner races with a hydraulic press.
Take your time and ask lots of questions.

Roger

Hi
Yes i am getting a magnetic stand with arm as well - these will arrive by Nov so I will have to wait a few weeks. But I am wondering if I should get a bendable octopus arm with clamp like I saw in some other youtube videos (somewhat like a gorillapod arm).

Did you mean tapered roller bearing when you said "taper roller inner races"? Parts number 25/26 in the diagram linked earlier? These are usually press-fitted on some kind of lathe machine I guess - I think the garage I am planning to get this done may have a press already, otherwise we have non-automotive small-time workshops a quick scooter ride away to get this done...

Thanks

The type I use have a main rod about 300mm long with a secondary rod that can be clamped in whatever position you need. The dial gauge is clamped to the second bar. I know about the "octopus" arm but I have never used one so I cant comment.
Taper roller bearings have 3 parts, the outer race, the inner race and the cage with the rollers. You need to press fit the inner race onto the diff. unit and please get it the right way round and yes I have seen people fit them the wrong way!!!
A hydraulic press is standard equipment in any reasonably sized workshop. If the guy picks up a sledgehammer, go somewhere else. You do not use a lathe to press fit bearings.

Roger

Got it. Yep I used the wrong word - not a lathe - a quick google search revealed my mistake. Press fitting the bearings should not be a challenge the machines are quiet common as you said, I’ve seen them in action here and there...

Thanks for the encouragement and guidance so far gentlemen.

Good news! I went back to the same garage to discuss the installation plan and procedures and the owner happened to be there this time. He told me they already have a .001mm DTI guage and to cancel the order I placed. I also found the old mechanic who used to service my car over there earlier in fact he was the one that installed the Ironman leaf and suspension kit on my car. He sounded quiet familiar and confident with the whole process so I'm quiet relieved now! I plan to get this fitted the coming Friday.

Sounds good. It's always better to work with someone you are familiar with.

Roger