Shugmobile upgrade - Now with throttle linkage photos.

[Shug]

You'd need the 4.2 final drive, plus the "B" gearkit that technically brings first and second higher (then the lower final drive drops the whole lot down) Just sticking the 4.2 FD into a standard box would give a really low first and second with that 2-3 gaps still there - but the whole lot would be lower, so 3, 4 & 5 would be much better. Gimme a shout if you want more info mate.

Distinct lack of progress this weekend due to the guy not being able to print out a label for the courier (claimed they never emailed it) so the courier left without the parcel... Should have it tomorrow.

[Shug]

Right - I have the bits. Update tomorrow with either joy or tears

[Rich H]

Lots of pics too

[Shug]

Okay doke - partial success. Stopped in my tracks by not having enough WMDs to continue. Will explain at the end.

So, here's the gearbox No 2 - much cleaner!



Also got this from the guy who sent the first gearbox - the correct 4.2 final drive:



Crownwheel and pinion - pinion is cast on the layshaft, as you can see.

So, getting this box apart was a bit more difficult as it was all sealed up properly (the other one had been apart then chucked back together) Has some advantages as well like steel caged bearings on the diff...



This is the other one, for comparison - spot the differences...



The eagle eyed will notice a major difference - this bit:



A Torsen diff. Uses a clever system of planetary gears to transfer torque from a spinning wheel to one with grip. Much less abrupt than a normal LSD - doesn't lock up as such. Everyone will give you an opinion on an LSD in an Elise and certainly I don't think there's much point unless you're going over 200bhp in terms of pace. The folks I have spoken to claim it changes the car for the better though - making the rear more throttle steerable and predictable. It didn't really cost me anything (this still came in under what you'll find most CR boxes for) so I figured I might as well find out for myself. If it doesn't work out, I have a selection of open diffs that can swap it out!

So, just to remind you - this box is a B6BST (B - CR gearset, 6 - 3.9:1 final drive, BST - torsen diff) and I want to change the final drive to 4.2:1 so it'll be a B4BST (B4BP is the Lotus CR box, with open diff) So, I need to change the layshaft with the FD pinion (shown above) along with the crownwheel on the diff - its the same amount of teeth (63) as the 3.9 final drive, but as the pinion has one less tooth, it's a different pitch.

So, to the layshaft:



Removed as per the other box in post 1 and shown standing up with the original layshaft still installed and the 4.2 one lying next to it. When the nut is taken off the top of the shaft (put both shafts back in the box without the selector forks, engage 1st and 3rd to lock the shafts, then it'll turn - left hand thread) The gears, synchros and shims all come off easily. They then just slide onto the 4.2 layshaft - just need to make sure that every washer and shim is on there - I'm going to take a chance that it'll shim up something the same, certainly most folk I've spoken to have never bothered with re-shimming them, it's really just for noise.



At this stage, I reached in impasse. The crownwheel is held on the diff by 10 (I think) bolts that are done up at 80 lbs/ft - or effing tight. Without a decent vice, I have no chance of getting these free, so dear old dad is taking them to a mate's commercial garage during the week, he'll buzz them off with air tools in 2 minutes.

So, next weekend, I should be able to put it all back together again and then it's a case of get my spare flywheel to Stu for lightening, buy a new clutch (might as well, the existing one is 92000 miles old) and then sort out a weekend to get the car to Domsport for a spanner sesh to take out one gearbox and replace it with this.

[Rich H]

[Mike Scib]

I am impressed mate, i would have no idea where to start

[Rich H]

Are you going to remove the bag of spanners included by rover to let you know you are engine braking?

[H8OAG]

Shug

Admire your patience.
The last gearbox I had in bits on the garage floor was a 1968 Mini Cooper S which had "lost " reverse.
I am thinking an exchange box or upgrading the internals from your own from one of the many gearbox specialists in the west would have been quicker /cheaper........but I am guessing that is not the point where your "special needs" are concerned

[Shug]

Would probably have been quicker - although I'd challenge you on the 'cheaper' bit Still, doing this as a technical exercise as well - it's just not as much fun when you've not done it yourself... If I wanted it done tomorrow, fair enough, but much like going somewhere in the Elise, I'm enjoying the journey just as much as the destination with this one...

Rich, I'm kinda hoping the rattling will be a lot less bad, seeing as I'll stick some decent gear oil in there and will at least attempt to check end-float on the shafts. Plus, mine has now seen 93000 miles of my good lovin (some lovely 3rd and 4th gear synchro crunches yesterday), so this will be significantly quieter anyway, I'll bet!

[Rich H]

Synchro on 1st is pooly on mine, 2nd is getting bad too... Might be a job for next winter if they last...

[Shug]

Just to drag this old thread up - gave it a few hours at the weekend, to swap gearboxes (okay, ended up the thick end of 2 days). Ended up inventing a new dictionary of swear words as almost every single bolt was seized and needed WMD to remove. The gearbox to chassis mount is possibly the most inaccessible piece of sh*t design in the whole car (although I'm sure it would have been easy when used in a front-drive saloon) There's one nut I need to get a spanner on, which the 421 manifold has totally blocked access to, so even the manifold needs to come off! That's the stage I'm at just now...

Also discovered oil pissing out of the crankshaft main seal. So, that's on order for replacement when I get the flywheel off.

So, hopefully in the next week or so, I'll have my shiny Stu-lightened flywheel, Helix clutch, and Shug-built box attached and running. No points for guessing which part will break

Have also decided to get that gold-plated unobtanium (well it must be, given the price) Jenvey throttle linkage and mount it under the throttle bodies like Mike. Guaranteed if the throttle cable is gonna break again it'll be on a run or on track, just like the twice it did it before.

[pearman00]

when you got that engine from me you could of had the CR gearbox as well and saved a lot off time
how have you been ?


good luck with the gearbox




Tony

[Rich H]

Keep us posted!

[Shug]

when you got that engine from me you could of had the CR gearbox as well and saved a lot off time
how have you been ?


good luck with the gearbox




Tony

Hah - you're right Tony! Still, it's been good fun building it. Engine is still going like a rocket - only one HGF now in about 40K since it went in, which isn't bad as it's on DTHTBs and probably around the 180 bhp bracket since it went into the car!

Sod all done this weekend after a last minute invite to some hot-tub action up the west coast at Eds.

[Shug]

Okay - another wee bit of progress last night when I took an hour or so and installed the Jenvey throttle linkage - photos to follow (forgot to take them) but it looks lovely and works a treat.