Griffon Gearboxes.

[Paul Andrews]

Could our gearbox expert Mr N, tell us/ me the differences between Griffon gearboxes GB 1 , GB2 , GB2 c and GB 3.

[Kim275]

Hi Paul - missed this one over my Hols - assume you refer to Geoff Nunn? I will ask him on Sunday at MAylandsea and post next week.........unless Scotty or maybe Colin could provide an answer?

[scott151]

Hi Paul.

To be honest I'm not up to speed with griffon boxes...

What I do know is that the early ones had Albion gears, the other gear manufacturers were PGT, the most sort after boxes are the jack knight ones, then I think the mk2 griffons gears were manufactured by Quaife.

There are also different gear sets, Close Ratio, Wide and intermediate Wide Ratio

Geoff Nunn would happily tell you but is not on the internet/computer..

Oh and early Griffons had a 5 spline clutch, the later 6 spline.

Scotty

[druid]

Griffon gearboxes

GB1 is a close ratio Albion box.
GB2 is an intermediate wide Albion box.
GB2C is a close ratio late PGT or Jack Knight box,
GB3 is a very wide Albion box.
To be sure what you have the only answer is to take it apart and look at the gears.
There are three manufacturers, 2 tooth forms (12DP and 10/12 DP) and 3 normal ratios (18 combinations?) although it is possible to get different ratios by playing with the individual gears.

Druid

[Kim275]

Thanks Druid much appreciated
By the way can you give us s list of all the letter stamps on Greeves engines
H = Dave Harper
G = Geoff Nunn ?
Cheers Kim

[Paul Andrews]

Thanks for the info Gentlemen .

[patsmash]

I have a griffon with GB4X stamped on the gearbox and the engine as no numbers apart from GP380 1 stamped on the head, any info would be much appreciated.......regards Pat.

[46T Sprocket]

Griffon gearboxes

GB1 is a close ratio Albion box.
GB2 is an intermediate wide Albion box.
GB2C is a close ratio late PGT or Jack Knight box,
GB3 is a very wide Albion box.
To be sure what you have the only answer is to take it apart and look at the gears.
There are three manufacturers, 2 tooth forms (12DP and 10/12 DP) and 3 normal ratios (18 combinations?) although it is possible to get different ratios by playing with the individual gears.

Druid

I have a GB2C Griffon gearbox Druid. How would I know who made it. Jack Knight or PGT? I know who J K is but who are PGT?

Thanks,
David.

[druid]

If you let us have the gearbox number we have a chance of identifying the gears that were originally fitted. The only real visible difference between the 2 manufacturers was that JK dogs were wider than PGT. (Precision Gear Transmissions)

Druid

[PeterJGreig]

Anyone seen the gearbox on fleabay "DOT Greeves James etc? (Please someone tell me how to insert the link!) Would it fit a Challenger, are they the same as Griffon? I do need wider ratios!

[46T Sprocket]

If you let us have the gearbox number we have a chance of identifying the gears that were originally fitted. The only real visible difference between the 2 manufacturers was that JK dogs were wider than PGT. (Precision Gear Transmissions)

Druid

Sorry for the late reply. I'll check out the number in the morning. I've been caught with crank and leaking boiler issues this past couple of days..

[PeterJGreig]

I was referring to the one in pieces.

[46T Sprocket]

If you let us have the gearbox number we have a chance of identifying the gears that were originally fitted. The only real visible difference between the 2 manufacturers was that JK dogs were wider than PGT. (Precision Gear Transmissions)

Druid

The number is 2355 Druid.

David.

[druid]

This gearbox was built in February 1975 so its a late one and I reckon fitted with the Jack Knight gears.

[46T Sprocket]

Thanks that's good to know. I've had it apart in the past to check things over and it all looks sound. It does find a false neutral from third to fourth now and then if I'm not positive in selecting the gear with my foot.