Custom transaxle

The diff is a 9" Nascar Detroit Locker with a 8.8 ring and pinion. the reason for the 8.8 is the 1.5" hypoid over the 2.5" hypoid of the std 9" as you know one of the big issues with using off the shelf parts is getting the input shaft under the diff carrier when the gear stack has 3.25" shaft centres. There is also less power loss through the 1.5" hypoid. Can't say too much at the moment but there is some serious up grades coming. This box is really the prototype and it will be refined as it is tested in Johns car. MSR stands for MAC SPORT RACING which is the name I have given to the home business I have started that is making uprights, bell housings and McLaren replica wheels.

Cheers Leon
 
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Rod i'll be putting 600+ ft lbs through it onto a 16" wide tyre so if it breaks you'll be the first to no.
cheers John
 
Let's hope it doesn't. Jerco stuff is tuff I was just wondering what the weak point will be. I wsh this would have been done a little sooner then I wouldn't have bought my Hollinger and would have more money for other things.
 
Input shaft would look to be most likely point of failure looking at pics, will depend on how much pain John boy inflicts on it, couple of other areas suspect as well, but Leon is being a bit cagey and selective with info on those areas.
 
What area's Jac, I'm happy to tell you what I know, and we'll find out what we don't know yet when John runs it. As for the input shaft it was bigger but John recons it wouldn't fit through the fingers on his clutch setup so we had to turn it down but at the EOTD is no smaller than the spline so should fail there first.

cheers Leon
 
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Hi Leon, I didn't know this thread existed, what you have done is fantastic. If only you had this a year and a half earlier you definitely would have had me as a customer. I know my Albins will handle the HP but your tranny looks so much more authentic. Really nice work!
Did you get my reply on the CV PVD ?

Regards, Udo.
 
Thanks Udo, I have just checked your thread and the PCD info.
My aim with this Trans was to give it an authentic style, I think Jac is taking my comment about up grades as to mean I think there are weak areas so I will clear this up now. What I was referring to was the chance that a Sequential 5/6 speed version was in the wind but I have heard today that the potential supplier feels there is not enough demand to invest in the R&D required at this time. Cheers Leon
 
As far as the internal parts there is nothing different to the last set up. I just dropped the Q/C and changed the Shift system. The shift now is the same as the Hewland LGs in its operation. The pinion is splined on to the output shaft with a locking nut same as the Corvettes do and the obvious change is the Case. The input shaft in the Lay Shaft is pressed and pinned which there are photos of.

Cheers Leon
 
Do you mean these pics Jac, there the only ones I have, first pic in 1st and sec gate

second pic in reverse gate
.
cheers John
 
Thankyou John, looks much better than what I assume was the MK1 version, might still give you some grief in use, guess you will find out soon.
 
Hi Jac, my only concern when I saw these pics was the clearances width wise might be a bit tight and cause shifter catching, and leon text me back to say he agreed and had already trimmed it down to eliminate the possibility, and he did say he gave it some hefty changes while the spun it with a big drill and it shifted great. so fingers crossed aye.

cheers John
 
I would assume that you would have an 'H' gate with lift flap for reverse at the gear lever to minimize that possibility. Im operating off Donnas lap top at moment so cant draw on pix to explain simply, but one concern is the distance from shifter rail centers to the point where the top shaft 'tongue' engages with them which tends to put a bending moment on the rails during a hard shift with the Jerico face dog engagement system.
 
Hi Jac yes I have a reverse lock out already in place fitted to the shifter, simple but effective,
Lift the knob which lifts a pin that rides on the side of the alloy block and you can move the lever to the left to engage reverse,



not sure on the thickness of the rail plates, ill soon find out if I bend them.
cheers John
 
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Ate your shift rails on linear slides or bushings? If shift quality is a little tough you could hard chome or put black diamond hard coating like they put on wrist pins? I have to say it looks nice and I like the quality of the castings!
 
The Shift rods slide in a Steel guide that has oil holes drilled in their length, the top shifter rod has bronze bushes at each end. I thought about the bending of the rods as well, they are made of Chrome moly and the tongues are made of stainless and at full travel they only stick out from the guide 15mm and they are 9/16" dia so I don't think there will be too much bending. I have no doubt there will be some teething issues with this first one, just hoping they will be minor. Bottom line is, its finished, it seems to work and it looks right which is a lot further than any other Transaxle build that I've seen on this site. As for the quality of the castings that will improve even more in the next ones as I will be fettling the pattern more to get an even better result and I'm going to address the concerns of the tongue length by moving the rails a little higher.
 
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