Has any one else had this happen to S/C gears?
Turbo Mini Forums

Well as I said in an earlier post going to the retro show me 3rd gear started to make a loud noise.
just started the strip down and found what is looking like a tooth from 3rd gear in the oil on the magnet.

Has any one else done 3rd gear in? just wondering what I do now, as you can't get better then S/C, maybe is just got weak with age as some of the teeth in the box are probably just over 2 years old.


I can't really conplaim as 3rd has been getting a real stick laterly.

Hope I can get parts other wise Avon is a big no, no.






MW

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

That doesnt look like a usual fatigue/crack failure to me, looks like the tooth has some wear near the base though. What gearset?

Edited by andeh on 3rd Jul, 2006.

I've seen the future and tbh its Pie

Well done on getting round to a strip down so fast!!!

I believe he runs minispares clubman set.

-MINI CLUBMAN 1380 TURBO-

against popular believe this gear takes some serious stick especially in your car willie.

but got to rember it may be a object which has got stuck between the teeth and has cracked it

we will find out tomox i recon on the post mortem i can see blood and guts every were. lol

always looking for them bigger bunches of bannanas

i think its plain and simple fatigue

with so much power going through the box

my advice would be .......................

change ALL the gearset and fitt all new bearings

yes cheers people I might well get a new gear set if there are any in stock!

Yes it's a mini spares set, thanks for clearing that up t3.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

Would a dog box last ok on the road?? never driven a mini with one in. as they seem to have wider teeth.

Can you change gear smoothly using the clutch?? as the car i drove with one in it crunched nearly every time going in gear lol.

Edited by Miniwilliams on 3rd Jul, 2006.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

soon find out matt as i've got one on mine! the mig's give them serious abuse and they last so we'll see. think its a case of getting used to it to stop the crunching...

oh dear, avon's going to be noisey!!

i dont think they will be any stronger they are designed to be used in a different way.

always looking for them bigger bunches of bannanas

I think some may be stronger,

for example the Quaife one may be as the teeth are a fair bit wider, so "assuming" the same material spec they should be stronger.

also theres the sequetial box from MBE that Keith Calvers been bandying about, suposedly strong due to the clean steel used.

I spoke to KAD about their 5 speed SC box a few years ago, they said it was designed to cope with around 260bhp, somthing to do with BDA's on an A series box I belive.

trouble is the ratios and the price. also I wonder what the longevity would be like, how much would the dog teeth wear? and what effect would this have on the rest of the box (and engine for that matter)

I am inclined to agree that it may have been debris though, it looks similar to a crown wheel faliure I had due to debris.

if it was debris - you'll have an indentation in the flank. I suspect this is a purely fatigued overload.
You can clearly see the smoother 'beechmarks' around the outer of the failed surface; the middle section was where it was torn away; as a result of the reduced area remaining (it had already 'cracked' upto the beechmarks at that point.
I've seen very similar results on gear test rigs before.

In 1st and 2nd the vehicle won't be able to put full torque thru the trans as the mini will simply accelerate (unless you hit it with a load of gas and boost on a sticky startline LOL)
3rd being a much taller gear will basically see nearer to 100% of the full engine torque compared to lower gears.
My thoughts anyway.

Edited by turbodave16v on 4th Jul, 2006.

I did it last year also, on 3rd gear.

that's pretty crazy. Why does it wear one tooth more than the rest then?

Also, am i right in thinking that a dog box doesn't have any syncros so you have to double declutch up and down the box to stop the crunching?

I run mine on the road with a dog box, I do double declutch to make life easier on it, unless i'm hammering it, and don't remember the last time I crunched a gear. If you're reasonably competent behind the wheel, and lets face it all of you guys who build your own cars must have a fairly good mechanical understanding, you'll find it no more difficult than driving a synchro box.

I drive mine to work and back and go shopping in it etc with no problems.

Dog gears are significantly wider than synchro gears, obviously without all that crap inbetween the gears theres more room to fit wider teeth. They have a much quieter whine to them as well.

danwebster nice pic mate, at least i'm not the only one.

looks like a KAD 5 speeders needed. how much is that going to be!

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

2.5 for a kad 5 speed, I know where theres a Jack Knight 6 (yes six) speed dog going for slightly less than that if you want the ultimate gearbox!

If hes selling the six, whats he replacing it with!

I've seen the future and tbh its Pie

yes i want it! however i'm on a shoe string budget believe it or not so i could only afford the £2.50 not the £2500 lol

Good point andeh!

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

you were spot on dave we stripped box yesturday and every thing else is spot on , so just a fatigue fracture.

as you say theres 100 torque going through 3rd gear as well as wind resistance acting baqck through the box aswell.


on the dog box saga to be honest i havnt realy studyied one next to another so cant comment but if the teeth are wider then in theory the should be stronger.

but i supose its a cost thing as in the long run is it going to be cheaper to buy a dog box set or just keep replacing bits of the normal sc set thats the big question.

always looking for them bigger bunches of bannanas

yes cheers for your help today hoggy.

The engines now on the box.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

blimmy she will be running tomoz then mate

always looking for them bigger bunches of bannanas

Got to be a record yer!!! engine out /stripped down/trip to minispares/rebuild/engine in.
Well done

-MINI CLUBMAN 1380 TURBO-

well got to try and get it done, i have some photo shoot coming up and don't want grease finger nails on them lol.

Engine in now just got to plumb it all up.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com