Broken gearbox casing

[Mathew Rimmer]

After replacing all the gaskets and still having a sizeable leak, am 99% sure that I have a cracked gearbox case on my BGH E7 HD 5 speed box. Being based in Switzerland impacts my options to get this fixed a little costwise. I have narrowed down the choice to replacing the case with a Quaife alloy one (have yet to confirm the the BGH internals fit OK) or purchasing a second hand 6 speed one

 

My car is a 190hp K series with 3.92 diff used mostly for sprinting and trakdays but some roadwork also. My gear ratio range is 2.75 to .86.

 

thoughts....

1) Quaife - looking through bchat there still seems to be some cracking issues even with this case. Cost approx £500 incl lid. No idea what sort of labour time is involved in transposing the internals.

 

2) 6 speed - concern about provenance of secondhand box. Doubts about whether 6th gear direct ratio and 3.92 diff are an appropriate combination. Lack of knowledge about why the 6 speed box is stronger (is it ?)

 

Any comments / advice gratefully received.

 

there is a s/h 6 speed on ebay currently, closiig on 31st. Anyone know anything about that ? What would an appropriate price be ?

[I reply to every thread]

A 2nd hand 6 speed of known provenace is worth £1200 - £1300 . Prices have fallen a bit recently as more have come onto the market with the race series box changes.

 

A 6 speed with a 3.92 is great on track or on B roads. Definitely not a "touring" option in my view. My HPC with a 3.92 and 6 speed becomes rather tiresome on long trips or motorway travel.

[rj]

With a 3.62 diff you hit the 8k RPM mark at some 135 mph if you run 205/55/13 CR500s

 

This leaves the top speed for an R400 (K series) to be 125 mph with a 3.92 diff which I would say is to low for any road use. Not because I use Vmax a lot, just to be able to live with the car.

[ECR]

I cracked a few type 9 cases and in desperation went for the quaiffe alloy box with alloy lid. As it is a lot softer and less strong than cast iron I would not have been suprised to see it fail quickly. I am pleased to say that it has shrugged off all I have thrown at it for years (and I seem to be hard on gearboxes)!

 

[Geoff Wilcx]

Have a similar spec car to yours which I also use for Sprinting and Hill Climbing from what I know of Swiss Hillclimbs V Max is never the #1 objective - go for the Caterham 6 Speed - I did with the 3.9 and have never looked back....but agree with other comments its hard work on long motorway cruising but this is not where you should be running a Caterham

 

www.geoffwilcoxphotography.co.uk

[Geoff Wilcx]

Should also add - if you are running as a road car and you source a previous racing 6 speed then you will most likely need to add speedo drive shaft - not a big task infact takes 15 minutes and could take most bits from your old Type 9 - you just need a few seals. Best you know so you can order the bits in advance.

 

www.geoffwilcoxphotography.co.uk

[Mathew Rimmer]

appreciate all the input. I guess yes I am unlikely to trouble vmax in most situations but am pretty confortable with current ratios

 

Anyone know if its likely to be a problem dropping bgh internals into a quaife case ?

 

thanks

[I.Mupferit]

I don't believe there is any problem with that Matthew. I certainly have known others who had BGH build up a gearbox using the Quaiffe aluminium casing.

[Mathew Rimmer]

Just spoken to BGH who say the Quaife case needs a lot of machining to take their internals. For me that tips the balance back to the 6 speed as a plug and play option.