Type 9 Gearbox in a Roadster

[andyf]

I have had the 4 speed and 5 speed type-9 gearboxes fitted to my roadster. The 4 speed box started making noises shortly after I recommissioned it and I though it was because it had stood idle for 18 years. But then the 5 speed box did exactly the same thing and started making the same noises. So I rebuilt it with new bearings and it was fine for a year but now it's started making the same noise It always starts with a "shing shing" noise off throttle in 4th then infects 3rd and 5th. I'm starting to think I have an installation problem. Could it be getting too hot as the transmission tunnel gets quite not? Or the other issue I have is that the engine mounts provided by Marlin are slightly offset so the gearbox mount is under some side load to straighten the engine and gearbox in the chassis?? Do other roadsters with type-9s have the same issue or is it just mine?

[philcoyle]

Re: Type 9 Gearbox in a Roadster

What type of propshaft do you have, is it the type with one doughnut and one u/J. If it is the doughnut they
do not like to be run out line, I have a type 9 box with a u/j at each end of the prop , I had it made 20 years ago and so far it has never given any problem, just grease the u/j once in a while. Mind you the type 9 gave up the ghost at the start of the lockdown when the circlip that keeps the 5th gear in place on the mainshaft split in half, why ?, but I was able to check my hydraulic concentric slave cylinder conversion and check the clutch plate for wear, 0.3mm in 11 years but I changed it any way having got that far.

[andyf]

Re: Type 9 Gearbox in a Roadster

@Phil, Mine has a U/J at both ends. The front one is sealed and I had to replace the rear one a while ago as it had started to wear. What seams odd is that they start off fine and then after a relatively short while they start to get noisy. I do wonder if the oil is getting too hot??

[jon_wilkinson]

Re: Type 9 Gearbox in a Roadster

What oil are you using in the gear box? There was a thread on here about the newer GL-5 oils damaging older boxes.

Edit: stevejgreen has an article about this on his Keepandshare site.

[andyf]

Re: Type 9 Gearbox in a Roadster

What oil are you using in the gear box? There was a thread on here about the newer GL-5 oils damaging older boxes.

Edit: stevejgreen has an article about this on his Keepandshare site.

I've used the Castrol and the Comma 75/90 Synthetic GL4 gear oil it's still lovely and clean...

[jon_wilkinson]

Re: Type 9 Gearbox in a Roadster

I've used the Castrol and the Comma 75/90 Synthetic GL4 gear oil it's still lovely and clean...

Not that then.

Like andyf I've not had the problem you're seeing but I've only had mine 4 years.

If it was the oil getting too hot you would have thought it would affect other Ford engined Roadsters.

[ggrum]

Re: Type 9 Gearbox in a Roadster

Is the gearbox fitted to a Ford engine or something else via an adapter plate. Not sure what the effect would be if the gearbox input shaft was mis-aligned with the small bearing or bush in the flywheel/crankshaft end. I believe the input shaft will tolerate a small amount of misalignment but there must be a limit. Just a thought!

[andyf]

Re: Type 9 Gearbox in a Roadster

Is the gearbox fitted to a Ford engine or something else via an adapter plate. Not sure what the effect would be if the gearbox input shaft was mis-aligned with the small bearing or bush in the flywheel/crankshaft end. I believe the input shaft will tolerate a small amount of misalignment but there must be a limit. Just a thought!

A good point. It's mated to a Pinto so it should be ok. The bearing in the flywheel was in good condition. What I'm wondering is if it is the needle lay shaft bearing as it was the only one I did not replace and I see that BGH Geartech list a variant for the 2.0 with a roller lay shaft bearing as an upgrade.

[milliemarlin]

Re: Type 9 Gearbox in a Roadster

One thing to check is that the gearbox is level longitudinally and laterally. The oil should be about level with centreline of the input and output shaft. A slight lowering of this level might cause the small bearing between the two shafts to run dry and fail. Failure of this bearing causes the two shafts to run out of alignment and the gears will not mesh correctly.

Did you, or could you, take a look at the internals of the old boxes?
Paul

[Ye Ol Ripper]

Re: Type 9 Gearbox in a Roadster

Andy, Obviously the propshaft is short on a Roadster but was there any vibration at a particular speed that could suggest that the propshaft may be out of balance?
Provided you replaced the uj joint with like for like joint it is unlikely to need rebalancing , however I have seen balance weights fall off the propshaft , so inspect that carefully.

[andyf]

Re: Type 9 Gearbox in a Roadster

One thing to check is that the gearbox is level longitudinally and laterally. The oil should be about level with centreline of the input and output shaft. A slight lowering of this level might cause the small bearing between the two shafts to run dry and fail. Failure of this bearing causes the two shafts to run out of alignment and the gears will not mesh correctly.

Did you, or could you, take a look at the internals of the old boxes?
Paul

An interesting thought. The first box was sold on and the second one was rebuilt with new bearings a couple of years ago. Apart from the bearings the internals are the same and after replacing the bearings it was quite for a while. Visual inspection of the internals including the bearings revealed no signs of wear. This is why I'm wondering if it was just new oil that made a difference rather than changing the bearings. If anything the box has been overfilled and the level is still high when I checked it at the weekend. I'm pretty sure that the box is level but I will double check it when I get a chance.

[andyf]

Re: Type 9 Gearbox in a Roadster

Andy, Obviously the propshaft is short on a Roadster but was there any vibration at a particular speed that could suggest that the propshaft may be out of balance?
Provided you replaced the uj joint with like for like joint it is unlikely to need rebalancing , however I have seen balance weights fall off the propshaft , so inspect that carefully.

The propshaft has no weights on it so no you have me wondering if I should get it re-balanced.

[duncan]

Re: Type 9 Gearbox in a Roadster

When you take the propshaft out have a look at the alignment of the two UJ's -

[andyf]

Re: Type 9 Gearbox in a Roadster

When you take the propshaft out have a look at the alignment of the two UJ's -

As discussed in this article on Universal Joint Phasing?

[andyf]

Re: Type 9 Gearbox in a Roadster

It looks like the next thing to check is the alignment of the flanges at either end. Apparently they need to be parallel in the vertical plane.