Broken Gearbox again Options?

[F355GTS]

Seems I've broken the selector on 4th again so am considering my options. Existing gearbox is a Quaife 5 Speed Semi Helicoil with long 1st, it has Quaife Steel Syncro rings that have been specially coated.

 

Does anybody have any suggestions as to what I could consider that would be stronger?

 

Engine is currently circa 235BHP Vauxhall, car used 99% for trackdays 1% road

 

Thanks

 

Mark

[rgrigsby]

You're not going to like the options... basically if it's breaking a lot you have two options.

 

1. BGH 5 speed sporting close 280bhp box and careful gear changing, seems to be ok in my 256bhp/201lbft duratec. I suspect if you're breaking a quaife SC box this won't be much use for you. I had a standard type 9 with steel coated rings and regularly broke it with my old car

 

2. Quaife straight cut dog box, it'll be fairly indestrucible but noisy as hell!! and they aren't cheap!

 

Out of interest what type of clutch do you have? that can have as much of an impact as the type of gearbox. If you've got a paddle clutch or something similar then I think a dog box is probably going to be the only option as they are pretty touch on gearboxes.

 

Rob G

www.SpeedySeven.com

 

 

Edited by - rgrigsby on 20 Jul 2005 20:05:37

[F355GTS]

Rob

 

Twin plate Superclutch with metal plates (rally ones i think that give a tiny bit of slip!)

 

Mark

[rgrigsby]

hmm so it's fairly agressive then? if that's the case I'd be suprised if anything short of a straight cut dog box is going to survive long based on my gearbox experiences

 

I wrecked my type 9 box with steel syncros about 3 times before I gave up with a paddle clutch, my current car has a normal uprated road clutch with the BGH box and it's OK at the moment. I suspect if I rushed a few changes it wouldn't take much to break it. You have to be fairly careful.

 

 

Rob G

www.SpeedySeven.com

[Paul Gibb]

Hi Mark,

I've been running a Quaife seq. dog box since April 2003 & during this time have worn out two sets of clutch plates on a QM twin plate clutch similar to yours. The dogs remain in good condition with only a bent selector fork and drive disc requiring replacing this year.

Paul

 

L7 FUN

[stevefoster]

Are you just rushing the changes tooooooo much?

 

Hants (north) / Berkshire club here

Area meeting pics here

My Racing here

 

[Nigel Riches]

Are you driving the gearbox beyond what it's designed to stand, yes, OK it's got a few up rated bits, but it was never envisaged by the Ford gearbox folk to have to withstand 200+ BHP.

You say the selector for 4th is broken again, why 4th, is there something wrong with some other part causing the 4th gear selector failure? How does it fail, the selector is usually a big chunk of metal fork to stir the gear into engagement with the necessary shaft.

Are you to quick off the clutch, not allowing sufficient time for all of the movement in the gearbox to complete, being particularly hard into 4th, as the red mist descends?

 

1982. 5 speed, clamshells. B.R.G / Ali. The True Colours.

[F355GTS]

Nigel

 

Sorry, my info was incorrect it's the syncro ring that's broken (probably 3rd according to Phil at R&R), these syncro rings are Quaife steel items with a special coating which hopefully would have lasted.

 

Steve/ Nigel

I suspect it's me not the box as you suggest so I''m going to put it back in and be more gentle until the Winter then maybe go for a sequential box

 

Mark

[knowley]

Sequential eh, nice 😬

[neil.cavanagh]

Mark,

Can't you get a flapping paddle thingy like the big blue car can come with?? That would solve the problems! 😬 😬

 

I'll get my coat....

[I reply to every thread]

Is it the VX torque that kills boxes - R500's don't have a reputation for going through 6 speeds?

[rgrigsby]

Hmm I think it's a combaination of torque and the agreesiveness of the clutch, my duratec is quite a bit torquier than most VX's and hasn't destroyed my BGH box yet although I have only done 3000 miles or so

 

Oh and the red mist scenario when on track or at least it was with me 😬

 

Rob G

www.SpeedySeven.com

 

Edited by - rgrigsby on 22 Jul 2005 09:44:50

[Peter T]

If i am able to re jig my finances, then i might sell my Quaife sequential 5 speeder, i am looking at changing to an Elite box.

 

Carbon Components from K9 Composites

 

[Mike Biddle]

Mark, I had a quaife six speed straight cut dog box in my 225HP VX for 5 years with no reliability problems.

[EFA]

Yes, Mines been in my car for about 4 years with only one isssue resulting from the fact that it was an early version. Quaife fixed it FOC.

 

The Dogs only wear if you are gentle with the box. Treat it hard and it will last for ages!

 

 

[EFA]

Oh and any syncro box using Ford type 9 synchros will break regularly with a 235bhp engine. Caterhams 6 speed box worked fine in my car, again for around 4 years. Prior to that the type 9 required repair at least 2 times per year.

 

Rob G - You will find out in time.... Sorrry 😳

 

 

[I reply to every thread]

So I should be OK with 232 bhp then 🤔

[F355GTS]

Peter

 

I'd like 1st dibs please if you do decide to change

 

Arnie, thanks for hte info, I asked Phil at R&R about 6 speeds and he suggested they would fail just as much

 

Mark

[ECR]

Mark

 

Breakages in type 9 boxes are a function of engine power and gear changing technique. If like me you have a higher power engine and a less than delicate gear changing technique you will unfortunately not get a type 9 to last. Those with gentler technique do have less ( but not no) problems. I broke casings (3), selector rods, synchro rings (both bronze and steel) but never selector forks for some reason.

Eventualy I opted for a quaiffe straight cut dog box in an alloy casing (which although "weaker" than the cast iron Ford part has not craked in the same way) with alloy lid. This box is essentialy the sequential box but without the sequential mechanism. So far it has proved indestructible and I am not suprised. If you look inside the box everything is VERY heavy duty and pleasingly the internals are very simple so there is less to actualy break. As you might imagine in use it is different to a syncro box and needs getting used to but after a couple of hours fairly quiet changes can be made and when you get used to the revs needed you can effect changes as quiet as any synchro box.

 

Barbara hates it though.......

 

 

[EFA]

Mark,

 

I thinlk Phil is wrong here. Remember he will see a lot of them as he maintains most of the race car transmissions!

 

The dog box Roger descirbies (with or without seq mechanism) is the holy grail here, but I am certain a Caterham 6 speed would be unlikley to break (they do break if you are a real hooligan (like PC 😬) or if you have an AP Surtrack diff and take corners with rear wheels in the air! Perhaps this too is one of Phils areas of concern. With the ZF the loads up the drivechain are much more controlled.

 

I'd second Rogers comments on driving style, but would add that it is engine speed (and hence load oput on the synchros) which is the T-9's worst ebemy.

 

Aves you'll be fine. You have to visit the dark side (>7,000rpm first). By persona, you're a long way off! ANd I told you to fit a 6 speed anyway!

 

 

 

Edited by - EFA on 29 Jul 2005 09:08:05

[Alex Wong1697456877]

if you have an AP Surtrack diff and take corners with rear wheels in the air! Perhaps this too is one of Phils areas of concern. With the ZF the loads up the drivechain are much more controlled.

---

 

EFA, could you explaine why? This might explain why my SPC semihelical synchro box lasted so well and ECR had so many probs with his T9's.

[EFA]

Alex,

 

Lifting a wheel on kerbs with a Suretrack causes the lifted wheel to recieve a significant incrase in drive torque, thus accelrating the wheel to well above road speed. When the wheel the contacts the road again a sudden shock load travels from the wheel back up the drivtrain. In the early 6spd box with a cross drilled 2nd gear, this would shatter or strip the teeth from the second gear. This is what happened to Peter C on th way home (IIRC) from Clash of the Titans at Curb.

 

Its less likley to damage a type 9, as the type 9 weaknesses are mainly the syncros, and the iron case if you have masses of power (this generally results in just a hairline crack and an oil leak, so no major or costly component failure).

 

Rogers issue was likley that he had a more abusive driving style and perhaps higher RPM capability than you did back then???

 

 

[Adrian Bruce]

Been following this thread with interest as I am in the process of speccing a gearbox to go with a Raceline 270bhp 2.3l Duratec engine. Chris at Raceline suggested the Sierra Type 9 (c/w with semi-helicoil) which is what Mark is running. Having also spoken to Quaife, they suggested that for track use, (I'm anticipating a 60% track/40% road use) the Dog Box would probably be the better option but also mentioned the noise factor.

 

Just how noisy can it be? Are we talking about a whine louder than the engine noise or just having to get used to a loud whirring?

[Alex Wong1697456877]

Dog boxes aren't noisy but have a graunchy shift until you get the knack of using them. Helical gears are quiet. Straight cut gears are in theory stronger and more efficient at transmiting power at the expense of being more noisy. The Quaife straight cut gears are noisy but it's quite a pleasant noise (unlike my Elite box which is VERY noisy). The semihelical is basically a helical gear set but with less of an angle - best and worst of both worlds. If I could, I'd have a semihelical dog box but I asked Quaife and they don't make this. So I think the best option for me would be a dog box with straight cut gears.

 

Having said that, I haven't given up on the elite just yet - it's so much fun to use!

[rgrigsby]

Arnie I'll have to wait and see but as you say it's revs that are the real problem with a Type 9. Hence I think it will be OK with the Duratec as it only revs to 7500 and tbh I don't get up there that often as it all gets a bit silly on the road.

 

As has been said you just need to be careful.

 

With my previous engine, an 8500rpm steel crossflow with a paddle clutch I wrecked a type 9 gearbox every 2 races so yes they do break if you're not careful 😳

 

I'm not racing at the moment so we'll wait and see.

 

As has been said ultimately a straight cut dog box is the holy grail here but as I'm mainly using my car on the road at the moment it just wasn't an option. (I'm of on the 3500+ mile USA trip in Sept!!)

 

Adrian it's worth having a chat with Chris at BGH Geartech and Phil at Road&Race, I can tell you know that Phil will say you have no choice but to use a dog box but Chris may have another opinion. At the power level you are talking about I think you're right on the engine of what is possible with an uprated Type 9, if you're careful it will work and will last but if the red mist kicks in and you rush some changes (which you just CAN'T do on a type 9) it will break.

 

In terms of noise on a dog box it's not that bad compared with the noise of the engine but they aren't quiet by any means, a test drive is probably the only way you're really going to tell if it's OK for you. I thought the other problem with dog boxes is the backlash due to the way they engage it means when you come on/off the power there's quite a lot of transmission noise/clunking.

 

Cheers

 

Rob G

www.SpeedySeven.com