Jelmer C31 Posted February 1, 2018 Report Share Posted February 1, 2018 I have a stock H190 in my 1983 Datsun Laurel C31. It has the 29 spline axles. I bought a OEM Nissan CLSD for it but when I took the old diff centre out and compared it I found out that it has a different height at the crown wheel flange and bigger crown wheel bolts. The crownwheel does fit but it sits to low. Any advice what to do? Quote Link to comment
datzenmike Posted February 1, 2018 Report Share Posted February 1, 2018 The differential is adjustable side to side for setting the gear lash. It may be within adjustment range but if not, a suitable shim between the ring gear and the body of the differential should work. Drill and tap the differential for the larger bolts. Quote Link to comment
G-Duax Posted February 1, 2018 Report Share Posted February 1, 2018 Use a spacer. Nismo used to offer them, but no longer. I made my 3mm one. I also needed longer ring gear bolts, found some from APR that fit with just a little trimming. 1 Quote Link to comment
Stoffregen Motorsports Posted February 1, 2018 Report Share Posted February 1, 2018 That's a typical example of "case break" where certain gears use a different offset. Make a spacer is described above. Make sure the bolts will be long enough too. Crown wheel = ring gear Bonnet = hood Spotted dick = ??? 1 Quote Link to comment
G-Duax Posted February 1, 2018 Report Share Posted February 1, 2018 Spotted dick = ??? = sick member 2 Quote Link to comment
G-Duax Posted February 2, 2018 Report Share Posted February 2, 2018 G-Duax, would a repair kit like the one from FRSport work? https://frsport.com/L-S-D--Repair-Parts-Mechanical-LSD-R200-Disc-Kit-12Kgfm_p_387519.html?gclid=EAIaIQobChMI48f1j6yH2QIV01mGCh2mHwdNEAQYASABEgLYTfD_BwE Yes sir. Quote Link to comment
Jelmer C31 Posted February 2, 2018 Author Report Share Posted February 2, 2018 The differential is adjustable side to side for setting the gear lash. It may be within adjustment range but if not, a suitable shim between the ring gear and the body of the differential should work. Drill and tap the differential for the larger bolts. The stock, open diff had no shims in it and is not adjustable like how a H233B is. Quote Link to comment
datzenmike Posted February 2, 2018 Report Share Posted February 2, 2018 My manuals show a page of how to measure and select side bearing shims to position the ring gear laterally in the case. But after checking I doubt up to 4mm. Quote Link to comment
G-Duax Posted February 2, 2018 Report Share Posted February 2, 2018 The stock, open diff had no shims in it and is not adjustable like how a H233B is. The H190 has the shims under the bearing, and typically they are very thin, so seeing them is almost impossible without pulling the bearing. Not like the R200, or my 8" Toyota that uses fairly thick shims on the outside of the bearing. So Mike is right, you are not going to move the diff over 3-4mm. There are 2 ways to come up with a ring gear shim. I originally took an old open diff, stuck it in the lathe, and machined a shim from the original flange. Now take a piece of ground flat stock, and machine, laser cut, or water jet cut a shim out of that. McMaster-Carr has the ground flat stock, which I bought a piece in case any one wanted a spacer when someone bought an LSD from me. Don't know if McMaster-Carr will ship out of the country. If not, anyone in the US can buy it, and ship to you. Ring Gear Spacers info: ID: 4.724" min - 120mm OD: 6.965" 8) 12.5mm holes on 145mm BC Thicknesses: 3mm, 4mm McMaster-Carr p/ns for flat stock: 3mm - 1388K45 4mm - 1388K57 Quote Link to comment
Jelmer C31 Posted February 5, 2018 Author Report Share Posted February 5, 2018 Thanks guys! About the 10mm bolts, is a ring gear easy to drill and tap? It looks to me it is very hard and won't let it drill and tap that easy. Quote Link to comment
Jelmer C31 Posted February 5, 2018 Author Report Share Posted February 5, 2018 It doesn't show shims on the outside so maybe Nissan did them between the bearing and housing? Number 38453? https://www.megazip.net/zapchasti-dlya-avtomobilej/nissan/laurel-2127/c31-6064/hjc31-617770/rear-final-drive-7750674 *edit* after reading G-duax his post again he explained it already! :blush: Quote Link to comment
G-Duax Posted February 5, 2018 Report Share Posted February 5, 2018 Thanks guys! About the 10mm bolts, is a ring gear easy to drill and tap? It looks to me it is very hard and won't let it drill and tap that easy. You can't ! You can't even chase the threads with a good tap. Too Damn Hard ! When I used ARP bolts in my ring gear, the threads were about 2mm too shallow for them to screw into. The holes were plenty deep, but a tap wouldn't cut that hard of steel. The only way to use them was to grind a slight taper on the end of the bolts. If your ring gear takes 10mm bolts, and your diff has 12mm holes, make some sleeves, to go into the holes. That is what I did. 1 Quote Link to comment
Jelmer C31 Posted February 6, 2018 Author Report Share Posted February 6, 2018 Thanks a lot again! How thick should the spacer be? I don't have the diffs at hand right now... Quote Link to comment
G-Duax Posted February 6, 2018 Report Share Posted February 6, 2018 The difference between the height of the flanges here: Quote Link to comment
Jelmer C31 Posted February 14, 2018 Author Report Share Posted February 14, 2018 I measured 2.62mm so I will make a 3mm thick spacer. A friend of mine has a special mill where he can grind it down to the desired ticknes. With the shims behind the bearings we will set the correct tooth contact. Quote Link to comment
G-Duax Posted February 14, 2018 Report Share Posted February 14, 2018 If you sit each in it's outer bearing race, on surface plate, or machined flat surface, and measured from that surface to the ring gear flange, then you would get the exact shim thickness you need. Then you could have the spacer made to that difference, and never have to touch the shims under that bearing. After all, that is the bearing that sets the gear mesh. The shim on the other side just holds the tension. The way you're measuring throws a whole lot of variables into the mix. 1 Quote Link to comment
Jelmer C31 Posted February 14, 2018 Author Report Share Posted February 14, 2018 That is why I will grind it to the exact thickness, you can't measure it with a set of calipers. There is to much variable in them. Quote Link to comment
G-Duax Posted February 14, 2018 Report Share Posted February 14, 2018 The only way to grind one to the exact thickness, is to measure the way I suggested. But what ever...... Quote Link to comment
Jelmer C31 Posted February 15, 2018 Author Report Share Posted February 15, 2018 Sorry, didn't wanted to sound like an *#&hole. Really apriciate your advice. I measured it like you said and your right: now it measured 3.02mm I found a big 3mm plate so I will make it out of that. Thanks! 1 Quote Link to comment
Stoffregen Motorsports Posted February 15, 2018 Report Share Posted February 15, 2018 As long as the shim is flat, it should be fine. There is some leeway with the side adjusters. I would make extra sure that the shim is totally, perfectly the same thickness all the way around, otherwise it will cause runout of the ring gear (crown wheel) that in turn cause tight spots with the gear lash. If it's not within .003" or .004" runout, you will have problems. Ideally there would be zero runout. 2 Quote Link to comment
G-Duax Posted February 15, 2018 Report Share Posted February 15, 2018 I use ground flat stock to make mine. But it's interesting how un-flat the stock flange was on the open diff I used to machine my first spacer out off. Closer to a Lays potato chip than a machined surface. 2 Quote Link to comment
Jelmer C31 Posted February 16, 2018 Author Report Share Posted February 16, 2018 Than it would be better if it is a bit thicker than 3mm and I would grind it flat on the mill to 3mm. This mill is used for heads, blocks and even shims. Quote Link to comment
Stoffregen Motorsports Posted February 16, 2018 Report Share Posted February 16, 2018 The hardest part about grinding that shim will be holding it while grinding. Maybe you could grind it before you cut it out. Yes, I used to chuck the carriers in a lathe to true them up also. They are usually pretty close though, within .002" or .003". Once you get it all assembled, check for runout on the back of the ring gear and also check the backlash in multiple places around the ring gear. Quote Link to comment
Jelmer C31 Posted February 20, 2018 Author Report Share Posted February 20, 2018 The hardest part about grinding that shim will be holding it while grinding. Maybe you could grind it before you cut it out. The bed of that machine is switchable magnatic so it just sticks to the surface. Crown wheel = ring gear Bonnet = hood Spotted dick = ??? Stoffregen = Dust Rain (in Dutch B) ) Quote Link to comment
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