Noisy in 1st and Reverse

[Peaks]

Any gearbox experts out there? 

My MkII Vitesse gearbox is making a growling noise in 1st and reverse. The noise does not happen all the time and sometimes it is quiet. 

When it is making the noise, it is loudest on overrun. The bearings sound fine. 

The box has only done about 5000 miles since full overhaul (but is wll out of any warranty)

Can anyone give me some ideas of what components I should be looking at in particular? 

Edited February 26 by Peaks

[Pete Lewis]

i would with any intermittent noise check for exhaust fouling on the chassis 

when  bit of engine torque tips the engine and you get contact 

Pete

[johny]

As Pete says discount all external possibilities first perhaps even getting the car securely up on axles stands and running it in first and reverse to try to locate the noise. However in the gearbox 1st and reverse gears are physically in close proximity so there could be something going on between the various components...

[Peaks]

Box came out last night.

Hmmmm, further investigation required, I think 

[johny]

Not good. Have you got the workshop manual? If not free download here at vitessesteve.co.uk

[Peaks]

I have thanks Johny

[johny]

Let us know what you find and the suspected cause as always good for reference....

[Works Spitfires]

Bent reverse idler selector lever, or incorrect spacer behind idler?

[Pete Lewis]

agree the lever is pretty tough but I would like  a £ for every bent one ive come   across

in the past 20 yrs     it is quite common 

if the gears fail to mesh i guess there is enough leverage via the gear stick to deform it 

and they take some heat and persuasion to reform .

Pete 

[Peaks]

So, the box was stripped today. Pretty typical Triumph gearbox maladies I'm afraid. The front needle rollers on the layshaft had failed; I'm pretty sure the rollers are supposed to be round, not square 😳 

The rear rollers had also started to eat into the shaft,  it at least those were round. 

The layshaft is junk, it had to be cut in two to remove it without causing damage to the case, and worse the inner part of the lay cluster where the rollers run is damaged. 

Looking at the price and availability of the lay cluster, I'm going to investigate having a sleeve fitted, but I won't know if that's viable until I've visited the local machine shop tomorrow. 

On the up side, everything else on the box and o/d is very good, but then you'd expect that from a gearbox which was overhauled 3500 miles ago.

Edited March 14 by Peaks

[Pete Lewis]

just a thought  

what oil was used ??  the shaft ...was this a poorly hardened after market one used  on the last rebuild

the needles have been seriously skidding . not rotating    quite unusual 

Pete

[PeteH]

Just (another) thought?. Are these loose or caged rollers? Is the correct number of needle rollers present? IF one of the needles had slippped out during assembly, the remainder would be able to run "skewed" to the parallelity of the shaft? In those circumstances the wear on them would/could be as you see?. "rubbing" rather than rolling would also scour the shaft.

EDIT:- Metal spraying used to be a solution, but it`s a long while ago, I don`t even know if anyone does it now?.

Pete.

Edited March 14 by PeteH

[johny]

Yes thats really weird! Was the oil port open right from the end of the layshaft to the hole inside the laygear to allow a flow through to lube the rollers?

As for sleeving the laygear I dont think its a simple job. It cant be too big a diameter as that affects the thrust faces at each end of the laygear and then its ID needs to be a very strange size to suit the layshaft plus needle rollers. Effectively the sleeves have to be custom made and then correctly hardened so as to as last...

[Peaks]

Pete H; good suggestion regarding one of the rollers slipping during assembly. That theory would add up looking at the evidence, although we'll never know for sure. 

Johny, I'm going tonsee what the machine shop says today. I'll report back on what they say. The bore size will be set by the undamaged part at the other end of the lay cluster. This is in perfect condition as it was new when the box was overhauled. 

[68vitesse]

Have a sleeved cluster in my Vitesse gearbox, parts supplied by Mike Papworth number in courier, who was also very helpful with advice.

Had two teeth break off third gear on the cluster which then wreck third gear on the main shaft.

Regards

Paul.

 

[Peaks]

Thanks Paul. I've just spoken to Mike and he's going to see what he can do for me regarding parts.

[johny]

1 hour ago, Peaks said:

Pete H; good suggestion regarding one of the rollers slipping during assembly. That theory would add up looking at the evidence, although we'll never know for sure. 

Johny, I'm going tonsee what the machine shop says today. I'll report back on what they say. The bore size will be set by the undamaged part at the other end of the lay cluster. This is in perfect condition as it was new when the box was overhauled. 

I still go with an oil problem because theres also too much wear for only 5000 miles at the rear of the layshaft and its unlikely to have had missing rollers in both bearings. That or the layshaft wasnt new or if so of very poor hardeness...

The good end of the laygear should be left alone and only the damaged part bored out the minimum necessary to allow a hardened and ground sleeve to be fitted to bring its bore back to the correct size. Theres a modification where longer rollers can be used to spread the load👍

[johny]

21 hours ago, Peaks said:

So, the box was stripped today. Pretty typical Triumph gearbox maladies I'm afraid. The front needle rollers on the layshaft had failed; I'm pretty sure the rollers are supposed to be round, not square 😳

Ive just noticed theres something that doesnt add up here. You say this is the damage to the front needle rollers but in the photo that should be the rear of the layshaft. Did you just get mixed up as its normally the rear bearing that suffers most as it takes the highest load from 1st and second gear....