gearbox rebuilt
Turbo Mini Forums

well i fished of the painting then the grouting of ones bathroom so thought with the time ive had left before the kides came home from school then off to dancing so decide to quickly rebuild ones gearbox.

after raiding the hords of gbox spares managed to find a decent a+ layshaft and put in my new second gear bearing from dsn.

few hours later hey prsto one rebuilt gearbox.

well all most for got and left one of my diif shims out do i had to quickly strip of my outpu casing and shove it in quick before the sealent went offff.

always looking for them bigger bunches of bannanas

you dont hang around do you

i bet you wouldnt be that fast in my garage...lol

for what makes it quick is
1. the box is pretty clean to start of with
2. i always use silicon sealer as it makes cleaning the gasket sufaces a two second job and a hours job.
3. i alreadey know the tolarances of the box which makes checking bits 20 times quicker ( with the exception of layshaft end float and idler gear which i still have to do.

plus spotting potential cockups at the right time like getting the outer and inner of the 4th syncro the wrong way round at the time eg just before fitting main bearings ect so its only a two min job to rectify.

pre planning for cock ups makes the job a hell of alot easyier lol

always looking for them bigger bunches of bannanas

is it ok if i hijack?

ive just put mythird motion shaft together with 4x new baulk rings and a 3/4 syncro unit, however the 3/4 syncro and baulk rings are very tight together, so much so it makes the gear box very stiff to turn with the layshaft in and the 2 gears turn together

will this wear in when the engine is run, or have i got something wrong?

I've experienced this a couple of times with NEW Sc boxes and four new baulk rings. What I've done these times is to fit good old baulk rings on ist and fourth. I'm not saying to fit rubbish ones, but GOOD ones. The new ones will wear, but you don't know how fast.

Let there be AT LEAST 1mm between the baulk ring and the dog teeth face. Possibly more when new gears are fitted as these are not always completely round. These will wear round and decrease the clearance quite fast.

yep - had that aswell...
NEVER had it when i used Rover Baulk rings, but have done with aftermarket ones. As Vegard says - i use older ones.

The gauge point on a synchro cone and ring is critical - I don't think the manufacturers of these realise or appeiate (or maybe care about) this...

hmm theyre supposed to be genuine ones, i may pop it apart again to have a look

Yes, as Dave says, the shape and size of the baulk ring and synchro cone is absolutely vital, as this is what generates the synchro action. They should be a close fit, but not so tight as to cause a problem.

Nic - measure the wear gap between the ring and tooth face as Vegard mentioned and report back...

i think the idea of calvers to gring the some off the face that ends up against the gear, this way the baulk ring will have bedded in then you give it clearance ,seems like a good idea to me , so long as you dont take too much of so the are only just locating in the syncro hub by there fingernails.
carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

nic i o have been messing around with the same problem, my new syncro rings stick on to the gears when he shaft is built up to the point where i cant turn the box. ive actually tried valve grinding paste on them to bed hem in a bit ( and thoughrly) cleaned parts off after) improved but not right. when i got the parts i remembered that i didnt like the look of the new ones. i think i might even put the old ones in back in on monday.

no longer a series, but still 1.3 turbo.

I use engine building lube on the b-rings and gear cones when building boxes.. Done this?

Edited by turbodave16v on 21st Jan, 2006.

being mr joe who doesnt know nowt you may have to excuse any technical errors in this post!

would making 'thicker' rings with the KC gearcutback work? is this something to explore? JKD are making custom rings at £14 (with obv limits), maybe worth concidering? Would this exaggerate the problems that this thread was started about. Alas im not clued up enough on gearboxes.

Edited by andeh on 21st Jan, 2006.

I've seen the future and tbh its Pie

I'm surpised JK can make a one-off for £14 to be honest.

All this needs is more attention to detail from the manufacturers or suppliers - not just of the rings but the geakits aswell...

sorry my bad, i meant specific rings for application, not 'one-off'

I've seen the future and tbh its Pie

ive had tight baulk rings which stick to the cone always use plenty of oil, also dont dispere on the 3/4 syncro always tight up both first and main nuts first befor you start to panick as this will pull the main shaft towards the main bearing and the same the other end.

especially common if you have fitted anew first motion shaft bearing and you hadnt seated it all the way on the input gear.

i always check baulk rings onto the cones first to make sure you have got at least .75mm to gear teeth.

some times on aftermaket gear kits the cone dia is slightly smaller thus making the baulk ring being a bit to close.

always looking for them bigger bunches of bannanas

well done mate!

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Do you find .75mm Ok?? How long service will they take then? It seems to be as new gear kits are a bit rough on synchro rings the first miles. On old gearsets this would probably suffice.
DOes it on new as well?

so if the manufacturers acctually made the partys more accurately and the rings from a more up to date suitable material , things would no doubt improve wear wise, .
i now also underatstand about not facing off the ring ,but nver imagined the dogs were that close together. so taking say .040 off some old baulk rings will lead to dogs clashing.??.

carl

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Unless I sit there with a batch of 10 Rover parts through the ages to accertain a tolerance band, then generate a stackup and calculate the effects, who knows.

All i do know is that at Zero weargap under 'worse-case' stackups, you want to have the ring 'just' at the unblocking point. This is often what dictates the geometry in the rest of the synchro - especially if you're working to a space envelope...
Simply making an assumption that it'llbe ok is far from ok IMO.

i would never grind the baulk rings unless it was apsot=lutly nessary eg i was to skint to buy new gear clusters.

i can see that it does work to a point as you are making the gap slightly larger between baulk ring engagement to the cone.

but if possible never throw old genuine baulk rings away as i have used them in the past as the new ones were slightly to big.

unless you go to the motorfactors with your gear clusters and chose a set from a box of hunderds.

if that makes sense.

always looking for them bigger bunches of bannanas