Rattly 3rd gear - any ideas why??

[jennyrebel]

Hi all
My F78 has developed a really rattly 3rd gear. It seems it has been leaking gear oil from around the gearbox drain hole which went unnoticed for a bit. Anyhow after refilling the oil there is still a nasty rattle in 3rd. No other gears seem affected. Does anyone have any ideas what might be causing this?

[typhoeus]

Daihatsu gearboxes aren't all that common, so what ever it is, you want to fix it before it gets expensive!!

[Peter Aawen]

The G/box casing wasn't damaged & the cause of the leaking was it?? If the casing has been hit hard enough to crack it, then it could be that the bearings &/or a layshaft has moved enough for the meshing to be outta whack, in which case, sorry, it's gonna cost!!

But if it was just that the plug wasn't done up properly or didn't have a sealant that worked so you ran it low on oil or dry for a while.... then it might just be a coupla dud bearings & maybe only an overhaul that's needed; but it's still likely that you to fix the rattle you are gonna hafta pull the g/box out & check bearings & gears etc, & that's not really going to be exactly cheap!!

Or you could track down a 'reasonable condition' second hand box now & start saving up like buggry to get it re-co'ed while you keep driving yours with the rattle until it fails!! If it's just a little rattle, there's a good chance it's just you listening for & hearing things to worry about cos you know it ran low/dry & you are worried; but if it really is that 'nasty rattle' you tell us it is, then there's probably no way around it costing a reasonably big fistful of $$ to sort.

Good Luck!!

[jennyrebel]

Ah - the cost is what I'm afraid of! Thanks Peter for your reply - I did have to have the casing welded a couple of years ago as there was a hole in in but they seemed to do a good job. I think the leak was caused the seal not being very sound on the plug. I will get it to a gearbox specialist this week and see what happens. I'm keeping my eyes out for a second hand gearbox too , but indeed they're as rare as rocking horse *****!

[typhoeus]

You should look on any Daihatsu forums you can find. I have a faint memory of hearing that a daihatsu delta truck box will fit, using the rear extension housing off your old box, . . . but I'm not sure of the details. You will have to do a little research

[jennyrebel]

Yes thanks Typhoeus, I had a quick look at the Delta but from what I can find out so far it will fit the Scat, no mention of a Rocky... Mind you I reckon the Deltas are just as hard to find as Rockys. Funnily enough the 3rd gear is less rattly today. Still having it checked out though.