Gearbox Input Shaft Needle Roller Bearing

[AlanG]

I'm reassembling a TR6 J Type gearbox (Cd 51088) following a rebuild and I've got a bit of dilemma and wondered if any of the gearbox guru's out there could advise me. When I reinstalled the input shaft it would not go fully home into the gearbox casing and that the gears were prevented from rotating freely. With it removed I checked the length of the new needle roller bearing (Catalogue Item 10. Pt. No. 158368). It measured .620" (15.7mm). The old bearing measured .589" (14.9mm). I assumed that this was the problem, the excess length preventing the input shaft from going fully home, possibly a bad or incorrect bearing had been supplied. However, Rimmers assure me that all their stock is the same and there been no other complaints. Checking with Moss they measured a bearing for me and it was a similar 15.6mm approx. If anyone has access to a bearing would they please measure it's length for me? Would the excess bearing length cause this problem or what else might it be?

Thanks

Alan.

[Rob Salisbury]

Hi Alan, It could be the syncro rings, some of the new syncro rings around these days have been made too big and cause the mainshaft gears to lock up when all is back in the casing, (try taking out the last ring and fitting the input shaft to see if this is the case), if so, how to get round this? You can mix and match with old but good, part worn rings, or the Art of Course TR Maintenance method 107B is to carefully file down the support pads of a couple of rings until clearance is obtained ... yes I've used this method and the gearbox is still happily working!!

Cheers Rob

[AlanG]

Hi Rob,

Thanks for that. I've not replaced the syncro rings, there was no appreciable wear on them. I have replaced all the bearings, the counter shaft, a broken .124" mainshaft thrust washer, a layshaft thrust washer and all the circlips. All endfloat measurments were checked.

Alan.

[reginald]

Hi Rob

Just a thought could you have assembled the the third gear on the counter shaft the wrong way round on assembly

as I nearly did this on my gearbox rebuild I noticed just in time even after watching this you tube video https://www.youtube.com/watch?v=V-GvcAS4A6k&feature=player_detailpage you will be able to assemble the gear box but gears will not rotate

 

regards Richard