260DET Posted June 13, 2003 Share Posted June 13, 2003 The obvious necessity for the rebuild came about though hitting reverse gear when downchanging from 5th on the track. No gearbox noises but reverse gear subsequently became difficult to engage which, as an inspection has revealed, was brought about by slight burring of the gear teeth. My particular gearbox is a FS5W71B type, same as that used from around '77 on in Zeds except for the gear ratios I believe. Around here it is referred to as a turbo gearbox and has quite a few improvements over earlier 'boxes. Wider gears for a start. Anyway, a stripping and inspection revealed a few problems other than the burred gears. The most serious concerns the front countershaft bearing outer race spinning in its aluminium housing and wearing the steel thrust washer and the housing. Enquiry indicates that this is a common problem. After talking with a Loctite rep it has been decided to use Loctite 609 when reassembling all bearings that locate in aluminium housings, plus in any situations where markings on steel shafts indicate that other bearings have tended to move around. As all the mostly NTN bearings were in good condition, they will probably be replaced with new NTN's although SKF's are a possibility. Trying to find out which is the 'best' brand of bearing is like listening to best beer recommendations, everyone has a different opinion. 8) As the left handed mainshaft nut was slightly loose, even though it was staked, Loctite will be used on it as well. In fact it will be used on all threaded fasteners. All the gears, shafts etc seem to be in good condition so it appears that loose bearings in aluminium housings are the weak point in these boxes. Comments? Suggestions? Quote Link to comment Share on other sites More sharing options...
260DET Posted June 23, 2003 Author Share Posted June 23, 2003 To complete the story, there are 'heavy duty' transmission bearings available from general bearing stockists, not all of which Mr Nissan supplies as a matter of course if you order through a dealership in my experience. One Nissan supplied bearing eg had seven balls, the HD alternative had eight balls. NTM for one have the HD option. On the sealed debris excluding bearings, they appear to be supplied pre lubricated. Which in my mind has the disadvantage of more drag, not good when the aluminium housed bearings tend to spin in the housing. They also don't get the benefits of circulating oil, particularly important when you are using a high grade synthetic gearbox oil. My thoughts of course eg for ordinary use where the gearbox oil will not be regularly changed the sealed bearings particularly on the (lower) countershaft may be a better option. Quote Link to comment Share on other sites More sharing options...
260DET Posted June 26, 2003 Author Share Posted June 26, 2003 Dunno if anyone is reading this but it helps to write it down anyway. 8) The problem of obtaining high spec bearings has been solved by getting a NTN replacement gearbox bearing kit from a bearing supplier. It appears that Mr Nissan, here anyway, has been cutting down his inventory by providing universal type bearings rather than special matched transmission bearings. The NTN kit was also significantly cheaper. Live and effing learn. Quote Link to comment Share on other sites More sharing options...
CU Zcar Posted June 26, 2003 Share Posted June 26, 2003 Who are you buying your bearing kit through? I assume NTN is the manufacturer...can you buy direct like that? When I rebuilt my FS5W71B the only kit I found was from a reseller (drivetrain.com...I think they were SKF bearings), but then neither did I look very hard beyond the 'net. Quote Link to comment Share on other sites More sharing options...
260DET Posted June 27, 2003 Author Share Posted June 27, 2003 The kit is put together by a bearing supplier, CBC here in Australia, I called it a NTN kit because it contains NTN bearings and I didn't want to confuse those out of Oz. One point of interest is that all the main and countershaft ball bearings have a C3 spec clearance for a specific reason. The input shaft, which sits in front of the mainshaft, also has a special bearing being a 3TM-6306CNXRX4V33 which is supposed to be superior to the stock 6306 CNXC3 for its particular purpose. Quote Link to comment Share on other sites More sharing options...
jp 280 Posted June 27, 2003 Share Posted June 27, 2003 since your in oz, have you looked into putting the gts skyline internals into an L serries desiel housing? i have all the parts sitting in the garrage ready to go, $100 for all new bearings (time and money are not on my side at the moment) so i havent got very far with it. i might pull it out and take a few pictures not sure how much stronger it will be, but my brothers skylines box has been holding up well. i payed $20 for the skyline box, so the total wont be any more then $150 for everything so i spose it wont hurt the pocket to much if it dosent hold up to the extra power. later, jeremy Quote Link to comment Share on other sites More sharing options...
260DET Posted June 28, 2003 Author Share Posted June 28, 2003 Good info, Jeremy. My 'turbo' box has turned out to be a C series box, not a B. Not much difference, slightly larger needle bearings for 1, 2 and 3 gears and a different front countershaft bearing. The C box was fitted to the R31 Skyline but not, perhaps, to the R31 GTS which I assume is the GTS you mention. So the GTS guts does fit into the diesel casing? If that casing is stronger than the usual Nissan casing that would be a plus. I don't want to have to go to a much bigger and heavier T5. Quote Link to comment Share on other sites More sharing options...
jp 280 Posted June 28, 2003 Share Posted June 28, 2003 R32 gts the centre plate lines up soo all you need to do is unbolt the gts housing and bolt on the LD housing, all done the reason for the LD housing is it uses the same size bearings as the skyline box and the other thing you may like to look into is the 3L VL holden commerdor (sp?) box we also looked at the gts25t skyline box, it looks like it will bolt up to the L series engine but its on to much of an angle and would also require some tunnel mods to fit it in there. all this info i get from my old man, who is a manual transmission specalist, so ill blame him if anything goes wrong later, jeremy Quote Link to comment Share on other sites More sharing options...
260DET Posted July 4, 2003 Author Share Posted July 4, 2003 Don't know what gearbox the RB30E engine had but the RB30ET has a huge box. Problem is those turbo boxes are very hard to find in reasonable condition and the ratios are not that great, 2nd gear is very low for a start. Quote Link to comment Share on other sites More sharing options...
jp 280 Posted July 6, 2003 Share Posted July 6, 2003 I put a few pictures in my personal gallery of the R32 gear set in the LD housing. I dont want to bolt it together yet, as i need to replace the bearings and i havent decided which tail housing to go with. Later Jeremy Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 6, 2003 Share Posted July 6, 2003 Personally I don't think there is much difference in quality as far as SKF and NTN go. Both are awesome companies to deal with too in my experience... offering our FSAE team free bearings for the whole car, every year. With that type of service, I can't recomment either enough! Quote Link to comment Share on other sites More sharing options...
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