Modifying FWD Volvo Gearboxes.

[Wobbly Dave]

I post this without positive confirmation that my 4th gearbox since transplanting in the quaiffe LSD, is possibly on its way out. I have an appointment to see a gearbox specialist (the same people who did the fit back in 2011) later this week.

This brings me to the thought that it is impossible to modify these boxes without later problems. Whilst I accept pushing them harder will limit life I am feeling a little frustrated.

Should I be looking to change to an M66 - is this any stronger? Should I go brand new & cover that?

The ford focus ST and RS appear to have better boxes?

So Hamish says the only real way to get 400+ HP is to go down the RS Focus route. I don't agree - it must be possible as our Swedish cousins seem to have it nailed.

Going to speak to Russell at RT Mechanics to see what they did to overcome their own challenges on the yellow peril.

Speaking to the gearbox specialist he is also of the opinion that modifying/ ramping up the power on these road boxes is putting them beyond their engineered limits.

Perhaps leaving the open diff as is - is the only way?

[Jamest5r]

I might be wrong but didn't the peril eat a few 3rd gears??

[Volvostorm]

Russ had probably where the gears would 'walk' up the layshaft and rub against each other, I'm don't know how he fixed it, but I think the gearbox layshaft was machined and fitted with shims so the gears couldn't touch.

There must be an answer, because as you said, not everyone has gone over to the M66 'box

[graemewelch]

your best bet is to speak to tim willams. see seems to have more exerience of highly tuned volvos than most. if i was in your shoes though dave id be very temped to do the 6 spd gearbox. after driving a s70 the other day i felt it realy did need the extra gear. itll give you the option of better clutches to. i think its a well known fact that 400 bhp is far from impossible to crack to the right set up

[t5 pete]

First off Dave you need to find out what is happening and what is failing with out that you will be none the wiser to what needs upgrading there is a thread on here some where with details of what Russ did im sure his internal gears were moving and actually needed some welding done inside to stop this.
Im not too much up into fwd gear boxes but I doubt there will be many if any stronger parts for our boxes they will need to be custom parts

[Wobbly Dave]

First off Dave you need to find out what is happening and what is failing with out that you will be none the wiser to what needs upgrading there is a thread on here some where with details of what Russ did im sure his internal gears were moving and actually needed some welding done inside to stop this.
Im not too much up into fwd gear boxes but I doubt there will be many if any stronger parts for our boxes they will need to be custom parts

I think you're right. I am just a bit miffed because I am soooo close on this build. It's just a set back & I won't know for sure until it's been looked at properly.

[ExternalError]

Whats colin running on his because he doesnt seem to have any issues pushing 400+bhp through it

[ROZER]

Whats colin running on his because he doesnt seem to have any issues pushing 400+bhp through it

I don't think the bhp is causing the problem its the torque don't think they like too much torque .

[smithy]

The m56 boxs ate the same as the m90 boxs internally .the problem with the m90 box is the syncro on 3rd can break so they tend to weld it on 3rd gear syncro .the m90 have been proved to take over 450bhp no probs

[Wobbly Dave]

Longevity however maybe compromised.

[siamblue]

If you are dealing with Hamish and Russ,then just do that,don't always go running to Tim because he is the last option,like a lot of people do,
Funny how people won't deal with Tim in the real world,but when there are problems he becomes the man to talk to and deal with..

[stribo]

I personally would look at going for a M66 if your current 'box has gone tits up. If you do go down that route, Oblark is the man to speak to, as he's fitting one to his 850.

[don kalmar union]

The Achilles heal of the old M56 gearboxes remains the baulk rings. They are particularly vulnerably to quick movements across the gates, although I have to say it is a very rare occurrence indeed in Volvo 'tuning' communities around the world.

The later M66 gearboxes incorporate baulk rings of different design and materials to the older M56 and they will take that sort of abuse for a lot, lot longer.

I have an M56 box in my S60 racer but it has been fitted with a set of dog gears which means that it will take many hours of running in endurance races without these problems, it also incorporates a quite aggressive plate type diff. not a Gripper, fitting an LSD does not have any detrimental effect on the longevity of these boxes ..... to my knowledge. I always use Red Line oil.

These dog gear sets are the only answer as there are no synchros, but they are not really even an occasional road car option, certainly not in a car used in town daily.

As has been previously mentioned Tim Williams has the most accumulated knowledge as a Volvo specialist of running M56 boxes with high output Volvo engines and is the only informed choice for honest and considered advice and potential remedial work by a country mile, apart, that is from the owners of such high output cars themselves who have in some cases learnt much too......

Regards, Don.

[don kalmar union]

On the subject of the M66 and its installation in the Focus ST and RS. An M66 from an ST will work, you just have to make some linkage changes which Tim Williams could do.

However, the M66 from an RS will not work as it has a different casing to other M66s to accommodate the fatter driveshafts used in the RS which are also specific to the Quaiffe fitted as standard in the RS which is not a direct swap for Quaiffe's unit for all other M66s.



Don.

[Nealevo]

Dave i have a M66 gearbox available, i have all the linkages and the rear subframe/engine mount to fit our cars, i was going to fit it to my car when i thought id smashed my diff........

[Wobbly Dave]

Dave i have a M66 gearbox available, i have all the linkages and the rear subframe/engine mount to fit our cars, i was going to fit it to my car when i thought id smashed my diff........

Hold that thought.

[don kalmar union]

Not to forget that a Gripper or Quaiffe for an M56 does need to have its flange altered to fit an M66....... they are two differently machined components.

Regards, Don.

[Jamest5r]

First dibs on your gripper/quaffie Dave

[Wobbly Dave]

Major cost implication with fitting the M66 is that the quaiffe diff is different - but I guess I can probably offset the cost by selling the QDF12J

If I have to change the clutch plate and all the rest then I might as well put Don's M66 Lightened flywheel and make the whole thing up.

This is not intended any longer as a daily driver - but occasion long distance road use, track days & quarters.

I think the change to the M66 with all the ancillary costs may well be prohibitive.

[deathrider311271]

Dave talk to Tim Williams will you. Do you have a problem with Tim?????? or is it just advice you have a problem with???