C4.1 build.... layshaft fouling gearbox

[Chrislong]

Hi Guys,
Ive fitted layshaft as described, ensuring the bearings are pressed in to location using a bearing press. Bearing roll freely in location - check.

Using the supplied spacer, and all 4 shims, the layshaft has a small amount of end float within the two halves.

Pair up the gearbox halfs, no other gears in location - only the layshaft, and it is very tight to roll. Upon close inspection I can see the layshaft teeth are fouling the internal of the gearbox.

Iv quickly run around the edges with a scalpal to remove any moulding bur, there isn't any anyway. No better. The fouling is significant, before I have even put any screws through - btw, just realised, no screws... (do I use the B4 gearbox screws?)

I plan to scrape away some internal material in the morning when im feeling a bit fresher. Im used to this, afterall I did plenty of this in the early stages of X-6 prototype running.

Anybody else suffering the same issue? How have you fixed it? Is it going to be dealt with by CML for future batches - or updated parts for those suffering with batch #1?

Looks good so far otherwise in all other respects. Looking forward to running it

Cheers
Chris

[westie]

All i used on mine was the one spacer sanded down a little, runs as free as a b4 trans.

[Chrislong]

Its not a spacing issue, its the gear teeth fouling the internal of the gearbox casing.

[westie]

Originally Posted by Chrislong

Its not a spacing issue, its the gear teeth fouling the internal of the gearbox casing.

Ah right, is it a b4.1 layshaft or b4 maybe some difference there maybe?

[Chrislong]

B4.1. The donor car is newish - used 5 times.

[westie]

Perhaps you have a dodgy one dude, ye olde dremel will sort it im sure.

[Crash]

I'm having exactly the same issue using a B4 layshaft. You can feel the gear teeth scraping the inside of the gearbox housing and is extremely hard to turn with or without the shims.

[Chrislong]

Yup cheers Westie, looking that way. Its significantly fouling, i can just about turn the layshaft and can count the teeth when it turns. Not usable in current condition so itll get modified tomorrow. No worries doing it, im suprised im the only one though.

[Dudders]

Ok this end, seems like the easiest bit lol.

Screws are being sent out, speak with Wes at CML

[Gaz_Stanton]

Mine is fine with B4.1 layshaft. Built as manual.
Use B4.1 gearbox screws Chris.

[Chrislong]

Ofcause, built as manual, no other way

I can do this stuff, im just sharing my finds here.

Gearbox sorted, took me longer to fit the tool to the dremel than to fix the gearbox. Its that easy. Lucky nobody else having same issue then? But if anybody is, I don't mind fixing trackside at Chadderton, I'll bring the dremel.

Pictures: +picture of dremel tool used.
DSCN4590.jpg
DSCN4591.jpg

[Crash]

Thanks for the pics Chris, I'll be getting my dremel out later today for the same task.
Ah the joy of the first batch - still love it though.

[Chrislong]

No probs mate, rolls very nicely now!

[Gaz_Stanton]

Originally Posted by Chrislong

Ofcause, built as manual, no other way

Sorry Chris, I meant I hadn't done anything different and mine was fine.
Just wait until you get it on track. Loving it from first run last night!

[Chrislong]

No worries Gaz im looking forward to thrashing it around a track

[Body Paint]

They must have sent you a special one Chris

Though I have to say I hope I never have to remove one of the bearings, I'd be amazed if they will ever come out.

[Chrislong]

LOL, yes agreed Craig, very tight. Thats why I used a press tool to make sure they are well seated. Imagine rubbing the shim down, only to find you didn't need to as bearings weren't in fully. haha.

[Chrislong]

Dremel already in my toolbox, anybody need this doing at Chadderton see me next week.. or wishbone dremelling for driveshaft clearance...

[blue_pinky]

So having built mine I made another observation with the layshaft fitting...

If you take just the layshaft and a bearing...and slide the bearing over the short stub on the layshaft you'll see that the stub shaft on the layshaft is longer than the width of the bearing.

When you assemble the two halves together and close it shut this tiny bit of shaft that sticks out then rubs on the bottom of the flat bottomed bearing pocket in the casing...making the shaft bind tightly.

Seeing there is plenty of wall thickness in this area, I very carefully took a drill to the case and drilled a small countersink (it could really do with being a flat bottomed counterbore....but I don't have any tools that would do that) into the middle of the flat at the bottom of the bearing pocket...giving the end of the shaft it's own pocket to go when it sticks through.

Then when you sand down the spacer as per the instructions you only need to just sand it a tiny tiny amount, if at all...just to loosen the fit a touch...literally just a few slides over the paper is needed to make sure it's completely free spinning.

Result...layshaft with negligible float that does not bind!

Note to CML...gearbox could really do with that extra pocket adding in to the machining, like the B4 gearbox has...just to make sure the shaft (and inner bearing ring) can spin in free air when it's assembled

[carpenterdean]

I did not have any issues with my gear box / layshaft, how come some are problematic and some aren't?