Gearbox Refresh?

[Graham]

So....I've been thinking again! (I hear groans!). There are plenty of owners who have had an engine refresh, me being one of them, but I haven't seen much, if anything, on gearbox refurbishment.
Some say they never break down so what's the point. Okay, that may well be true, but they must wear, and I know that mine after 130,000 miles is pretty noisy.
I think of this every time I see a gearbox for sale and wonder if I ever bought one would I have it refurbished? Depends on the mileage? How many miles would be few enough not to bother?
I probably never will, but like I said, just thinking.........
Anyone else ever pondered this?

[wixer]

This a timely post as if you've read my rebuild post, I'm mid way through dropping the gearbox for a clutch & driveshaft replacement but I was thinking that this could be an opportune time to get the gearbox re-freshed or at least inspected. But mines done nearly 190,000 miles & shows no signs any issues.

I too would be interested in any recommended specialists

[goldtop]

I've got a vague recollection that Kare's (Silver Surfer) tame mechanic did some gearbox work for him. Although that might have been box-swapping as opposed to refreshing or shorter-gear conversion.

Are NSX gearboxes especially weird, so much so that a generic gearbox firm would be a bad choice?

[Kaz-kzukNA1]

In case you missed this thread….

This is a great write up by our late goldnsx - Thomas.
http://www.nsxcb.co.uk/showthread.php?14344-My-gearbox-revision-thread


(http://www.nsxcb.co.uk/showthread.php?14344-My-gearbox-revision-thread)Eventually, all Trans needs attention depending on the mileage/usage/etc.

Obviously, it requires the removal of Gbox and depending on the parts replaced, requires specific measurements/adjustment, etc so not something you would do as an annual maintenance.


In my view, the end result of any Trans refresh reflects more the experiences of the very person than the Eng Refresh.
At the factory in early days, each trans even went through fine adjustments for the shift feeling.


As a regular check at the time of MTF service, you can inspect the MTF meshed filter for metal powder debris mainly from the regular wear.
Please replace MTF regularly, by the way.

Big bits like the damaged gear teeth would be trapped at the magnet plate so can't inspect easily.

At idle rpm, disengage and engage the CL while in neutral without moving the tyre (no movement at the DF, countershaft).
If the grinding-like noise disappears, your bearing is pretty much done.
Not going to explode but at some point, needs to be addressed.


If you start feeling some grinding at the gear change and if there is no issues around the CL mechanism, time to start preparing for the Trans refresh.

For some reason, Honda went with the ring spring design around the synchro, unlike the ordinary key mechanism.

I don't know the level of manufacturing accuracy required but even a tiny difference would change the shift feeling or even cause damages.
At the time of Trans Refresh, just replace all of the synchro.
However, there was a problem with the new ring spring out of the bag so be careful if using super-old stocked item.

Lots more but enough as the starter.


Kaz

[Graham]

Well, a lot of thoughts. I know that when I push the clutch on the car at idle it gets a lot quieter. I’ll need to investigate that further, but I had an operation yesterday and can’t lift anything for 6 WEEKS!!!!! Also the instrument cluster is out so it won’t happen for a while.
My next post on this might be in a while.