Punto (Mk2/2b) play between Inner cv joints and dif?
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Punto (Mk2/2b) play between Inner cv joints and dif?
multipete
Established member
Is the shim stuck to the bearing? Get a small screw driver and see if you can prize any thing off the bearing surface . Does it look like it has been stripped before?
multipete
Established member
multipete
Established member
Adjusting Diff bearing preload process
I will be completely honest that looks way past my skill set, I will have another look when I get in from work, really appreciate the time and help !
I will be completely honest that looks way past my skill set, I will have another look when I get in from work, really appreciate the time and help !
The video where the diff is assembled is showing the bearings are worn out or the shim is not present - that movement is nothing to do with any other worn differential gears. The diff should be slightly tight to rotate due to the few thousands of compression the bearing is put under by the preload calculation when the correct shim size is fitted.
Selecting the correct shim is easy. just get some solder and compress it between the bearing and bolt on plates. Measure the squashed fixness of the solder and then add the thickness of the published/available preload. The preload is a small amount of additional shim thickness to make the bearings tight to turn when cold. Fairly obviously your bearings are not tight to turn!
Thanks for the info ! Provided I can manage that without somehow messing up, any ideas where I can buy the shims ? Thanks !
In regards to my own question, just found this
https://www.bearingkits.co.uk/LARGE...ADJUSTING-SHIMS-to-150mm-DIAMETER/C41-1-0.htm
If the movement shown in your video is all due to bearing play, then that's quite a lot! Wasn't there any noise? gear whine, bearings scrunching, etc. That's quite a lot of movement. Must give my Panda's shafts a "wiggle" also maybe my boy's Punto.
Well I've made some progress today, I found the shim !! After looking at my video again at work I thought I could see a metal ring as has been described, on the outside of the n/s bearing! So it was in there, I added some solder and refit the shaft and plate, removed after and it appears there's maybe half a mm space ? Do you guys recommend I just get a 1mm shim and Chuck both back in ?
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https://i.imgur.com/5RV3nZ2.jpg
https://i.imgur.com/UdQAVCV.jpg
im starting to think i just need to replace the bearings.
https://i.imgur.com/UdQAVCV.jpg
im starting to think i just need to replace the bearings.
Absolutely not. Setting up bearing preload is quite an exacting science. Just chucking in a shim which you think is roughly the right thickness is a sort of engineering version of Russian Roulette. Get it too slack and you might as well not bother, too tight and the bearings will wear rapidly and could even seize. The forces acting on final drives are amongst the highest in any part of the power train, it needs to be right.
I've never rebuilt one of these boxes but have done similar assemblies. Typically this type of preload would be set up with the pinion not in mesh with the crownwheel so that the effort needed to rotate the crownwheel/diff assembly can be monitored as the shimming is adjusted. It's very precise stuff.
I've been looking for a video for you but haven't found one so far that shows a FWD setup. I'm off to bed now but I'll keep looking tomorrow and post it if i find one.
What's still puzzling me is that with the amount of play you were showing us I would have expected it to be making some obvious sounds of distress?
Point taken ! Well I didn't hear anything, car drove fine, changed gears fine, no vibration I'm aware of, just during the mot they told me there's play between both inner CV joints and the diff, thanks again
If you had new bearings in there the preload is 0.12 mm. The differential casing will flex but the bearing is still very tight in the differential.
Did you notice if the movement was reduced when you had the solder in there?
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multipete
Established member
Measure the squashed solder,add 0.12 and that’s the size of the shim you need. BUT why is the pre load altered? (1)some one been messing,unlikely .(2)bearings starting to go and need to be replaced. My advice,Check bearings and replace as necessary .
i'm going to order a bearing kit, but i just had a few questions, ebay says this will fit ( https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=113542549570&_sacat=0)
do the bearings need to be pressed on in any way, its been like 4 years since i've touched a diff XD i cant remember.
do the bearings need to be pressed on in any way, its been like 4 years since i've touched a diff XD i cant remember.
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Oh dear! I am completely wrong about the 3mm preload!!
I misread the "0.12". That must be 0.12mm!
Sorry!
Full instructions for the palio gearbox are here. More or less exact same gearbox as Punto.
https://www.fiatforum.com/downloads.php?do=download&downloadid=549
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Thanks very much judderbar, I've copied that to my files - gearbox info is so hard to come by now that Haynes don't include it any more. There is a lot of mention of "caulking" in it. Doesn't seem to be the same as I would understand from the word caulking - which I would associate more with seams in bodywork or home decorating. Any idea what they mean?
JDP 12. You ask whether the bearings need pressed in? Well not really so much as far as the casing is concerned but that is pretty irrelevant as they will be a very very tight fit on the diff cage. You will not get them off in situ. The diff casing will need to be split so you can remove the crownwheel/diff cage assembly and work on the assembly on the bench. Not only will they need pressed on (you might manage to drift them onto the diff cage with a punch if you heat them in the oven first, but I wouldn't try as you are likely to knock lumps off them) but you will usually find they are very stubborn to get off! If you are not a regular enthusiastic car maintenance/repair sort of guy/gal with a good selection of tools you will probably find this to be quite a challenging "adventure"!
Good luck with whatever course of action you decide on - hope it doesn't hit your wallet too hard.
Kind regards
Jock
JDP 12. You ask whether the bearings need pressed in? Well not really so much as far as the casing is concerned but that is pretty irrelevant as they will be a very very tight fit on the diff cage. You will not get them off in situ. The diff casing will need to be split so you can remove the crownwheel/diff cage assembly and work on the assembly on the bench. Not only will they need pressed on (you might manage to drift them onto the diff cage with a punch if you heat them in the oven first, but I wouldn't try as you are likely to knock lumps off them) but you will usually find they are very stubborn to get off! If you are not a regular enthusiastic car maintenance/repair sort of guy/gal with a good selection of tools you will probably find this to be quite a challenging "adventure"!
Good luck with whatever course of action you decide on - hope it doesn't hit your wallet too hard.
Kind regards
Jock
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For caulking they mean staking, raising the surrounding metal with a sharp punch to retain another part
Aaah! Staking. As is used to retain universal joint bearing cups (bring back circlips I say!) and in many other applications?
Thanks judderbar, that's made it all clear now. You learn a little - sometimes a lot - every day.
