LT77 & 56K, worth rebuilding?

[Griffith77]

Engines out and being rebuilt, my minds now turned to the box

Having seen how straight forward it is to get in and out i'm wondering if its worth taking out now while the engines away and getting it checked over or worrying about it when i get a problem.

Nothing obviously wrong apart from a bit of spary on the tunnel around the tail bearing so maybe a weak seal but gear changes are fine and so are oil levels

What's people’s experience of these boxes? Any inherent problems/weaknesses

[carsy]

Mine had done 65k miles and 2nd and 3rd synchros werent good. I therfore had it rebuilt. I think it really depends on how much spare cash one has and how much you enjoy working on the car. Do now and forget or leave it and risk having to do it again sometime soon.

I think if yours is ok i personally would leave it apart from some fresh oil.

Even if it has to come out in the future its not the end of the world and will give you the excuse for yet another day working on the car.

[spend]

It's quite possible that the prop shaft UJ's are the type with lube nipples and that has caused your 'spray'.

I'd renew the propshaft UJ's & clutch before even contemplating a box rebuild if I was you. Dropping the box out so you can do a few other jobs whilst you wait may be worthwhile:

Handbrake linkage
Fettle upper chassis rails
bush / ball end that gear lever sits in
box rubber mounts

...?

[Griffith77]

thanks gents - Spend, good call on the lube nipples, i'll look next time i'm under there.

Think i'm tempted as it's obviously easier with the engine already out and it gives me a chance to check the other points raised for wear.

Also means if i do need to pull the box at a later stage the bolts will be easier to shift

[spend]

I don't think the lube nipples help or leak.... It's just that when you force lube into them it seems to just escape through 2 of the seals on the 4 legs ~ which always begs the question of whether lube is getting to the other side. TBH these days I'd rather fit the ones without grease nipples (which seems to be the way they nearly all come anyway nowadays).

Probably sounds a bit odd, but becomes blatantly clear when you've replaced a few & tried to grease them Do strongly consider renewing the prop UJ's though - they take quite a hammering.

[DarkMatter]

spend said:

Do strongly consider renewing the prop UJ's though - they take quite a hammering.

Would you expect to detect play in these UJs, when the prop is removed, by simply turning the flange relative to the prop? That method always worked for me when I owned Herald/Spitfire/Vitesse/GT6 cars but I'm wondering whether that method is adequate to detect wear on a Griffith UJ?

[spend]

It's a lot of turning & flexing to detect any overly stiff/slack point, which in itself requires a good feel & judgement... For the cost and particularly if the prop is practically out I'd replace them. I'd guess sensible intervals to be @ at least every 50k (they are std GKN Hardy Spicer parts) as they do seem to take some stick as well elements + exhaust heat? I also suspect that any backlash in the whole drivetrain just accentuates wear on the other parts as you get the effect of a snap torque as the lash is taken up?