30 replies to this topic

[babsbrown]

Hi guys,

I'm thinking of changing my FD by changing my drop gears while the engines still in. (Using roller drops to negate shimming the idler)

I have an old idler gear I can weld a bar on to lock against the crank to undo the input gear nut.


But the problem will be when I torque the nut up again. Because the idler gear tool will be a helical gear not straight cut.

With this in mind can I simply put the car in gear and lock the flywheel to Tighten up the input gear nut?

Thanks, Luke

[babsbrown]

I appreciate sc drops will be loud but I have hearing protection and I like the idea of being able to change my FD without taking out the engine or diff. Especially if I change from using the car on the road or hill climbs etc..

[Spider]

It might be possible to do this job 'in car', but personally, I wouldn't contemplate it, so much easier on the bench and you can see so much more. It's only a ~ 30 to 40 minute job to get the engine out.

[babsbrown]

It might be possible to do this job 'in car', but personally, I wouldn't contemplate it, so much easier on the bench and you can see so much more. It's only a ~ 30 to 40 minute job to get the engine out.

Aye probably so to be honest. I'm trying to think how I'd do it off the car. I'd have to split the gear box and lock 2nd and 4th once I disable the selector to lock the gears, I presume. I wonder how they changed them quickly trackside.

[DeadSquare]

Somebody used to sell a substantial device that bolted in place of the starter and locked the starter ring.

 

I find that an old bearing shell works to lock the starter ring.

[babsbrown]

Somebody used to sell a substantial device that bolted in place of the starter and locked the starter ring.

I find that an old bearing shell works to lock the starter ring.

Aye I bought one of those from jbfabrications a while back. Locks it in really tight. Do you think locking the flywheel and 4th gear would be enough? I don't want to chip any teeth.

[Spider]

You won't need to split the engine off the Gearbox.

You can drop the Diff out (assuming this is a Rod Box) and select 1st and 4th from there.

Take the Flywheel off, Flywheel Housing off and your Drop Gears are right there.

[KTS]

 

Somebody used to sell a substantial device that bolted in place of the starter and locked the starter ring.

I find that an old bearing shell works to lock the starter ring.

Aye I bought one of those from jbfabrications a while back. Locks it in really tight. Do you think locking the flywheel and 4th gear would be enough? I don't want to chip any teeth.

 

 

locking the flywheel this way needs the transfer case to be fitted which means you can't access the first motion shaft nut ?

[sledgehammer]

Thinking out loud (and probably wrong in many ways)

 

Get a dead clutch plate , cut the outer off , you want the spline

 

weld a plate / strip / bar - from the splined section that will extend to the block , 

 

that can be wedged between the clutch spline / gear , and something on the block
 

This should lock all 3 gears , and access will be easy , will only work on straight cut gears - helical will want to jump out .

 

Hope this makes sense

 

If in any doubt - ignore this

and as above , the starter hole / f/w housing, will be covering the gears .

Edited by sledgehammer, 26 June 2025 - 08:31 PM.

[Gaz66]

Just change the CW/P, it's the same amount of work (nearly) 😁

[DeadSquare]

 

 

Somebody used to sell a substantial device that bolted in place of the starter and locked the starter ring.

I find that an old bearing shell works to lock the starter ring.

Aye I bought one of those from jbfabrications a while back. Locks it in really tight. Do you think locking the flywheel and 4th gear would be enough? I don't want to chip any teeth.

 

 

locking the flywheel this way needs the transfer case to be fitted which means you can't access the first motion shaft nut ?

 

Silly me. The OP mentioning "Locking the Flywheel"  sidetracked me into just thinking about slackening the flywheel bolt to remove the Transfer Case.

[babsbrown]

Thanks gents,

I was mistaken with that too. As you guys mentioned there is a tool that can be made up ro lock them in place. I'm hopefull I can get my hands on a used clutch and make something out of that.

[timmy850]

My thinking is you'd be much better off to remove the engine to swap the drop gears.

 

But if you're removing the engine you'd be better off changing the diff ratio rather than the drop gears

[imack]

https://youtu.be/UuV...DxqmnATw1Ls_tr0

[Ethel]

The issue I see being most fun with the lump in situ is setting the idler end float*. You might side step that with a roller bearing idler, but the cost isn't likely to be favourable compared to changing the final drive & there won't be that much difference in spannering effort required.

 

I think I'd start by playing around  with the various ratio combinations (Guessworks' gizmo?) and see what would be worth the money.

 

155/70/12 tyres would be way easier - if they'd give you the quick change ratios you're after.

 

* My contribution to the daft ideas symposium - drill a hole for a bung in the middle of the idler gear housing in the tranny case. It could let you measure the end float thru' the hole with a dial gauge. BFO magnet or up ended engine permitting