Quaife QBE62G Final Drive Ratio

[Randy Folsom]

I need some help. I just picked up a Quaife QBE62G for use in an RCR40. It is still in the original crate. The seller did not know if the final drive is 3.5 or 3.75. There is no label as far as I can tell. Does anyone know how I can determine the final drive ratio other than by contacting Quaife. I feel bad about contacting them since I bought the box second hand.

 

[Ryan L]

presume you could take the cover of and see what is marked on the gears.

 

[Neil]

presume you could take the cover of and see what is marked on the gears.

Or simply count the teeth on the ring & pinion gears.

 

[Randy Folsom]

I am pretty sure splitting the case to count the teeth would end badly .

 

[Neil]

I am pretty sure splitting the case to count the teeth would end badly .

No worse than "presume you could take the cover of and see what is marked on the gear"

 

[Joel Heinke]

Engage the transmission into whatever gear is 1:1, mark the CVs so you can measure the amount they turn, rotate the input shaft 3.5 turns. If the CVs turn 1 full turn, then you have a 3.5 ratio. If it takes 3.75 turns of input for CVs to turn 1 full turn, then you have 3.75. Much easier than opening it up.

 

[Randy Folsom]

I may have do some math because none of the ratios are 1:1, that should work. Thx much.

 

[JP Verweij]

Gear Ratios:

1st			2nd			3rd			4th			5th
2.533			1.619			1.200			0.929			0.742

Final Drive Ratios:
3.500
3.750

 

[Randy Folsom]

Thank you, but the question is which final drive. Two options from the factory: 3.5 or 3.75. The seller says he doesn’t know.

 

[Howard Jones]

Put the grbx in 4th gear, That is the one that is closest to 1 to 1. Now turn the inout shaft one full rotation exactly. Mark witness marks on the input drive flange and adjacent case with a felt pen. Do the same on one of the output flanges and case. Now turn the input shaft exactly one full rotation. If the output shaft has turned 3 and a half turns then you got a 3.5 to one final. If it has turned 3 and 3/4s of a rotation then it is a 3.75.

 

[Neil]

Put the grbx in 4th gear, That is the one that is closest to 1 to 1. Now turn the inout shaft one full rotation exactly. Mark witness marks on the input drive flange and adjacent case with a felt pen. Do the same on one of the output flanges and case. Now turn the input shaft exactly one full rotation. If the output shaft has turned 3 and a half turns then you got a 3.5 to one final. If it has turned 3 and 3/4s of a rotation then it is a 3.75.

Input = 1 rotation, output = 3.5 rotations??? Backwards.

 

[Ryan L]

0.929 x 3.5 turns of the input shaft = 1 rotation of the output shaft in 4th.
0.929 x 3.75 turns of the input shaft = 1 rotation of the output shaft in 4th.

The pinion gear is smaller than the ring gear, so it will have to turn more times to spin the ring gear a full rotation.
if its got an open diff you will need to make sure that both left and right output flanges rotate equally, so you will need to mark both of them and make sure they stay in alignment. If it's got an LSD it's probably not going to free wheel and just spin one output shaft, but still worth watching to make sure it doesn't happen.

 

[Neil]

0.929 x 3.5 turns of the input shaft = 1 rotation of the output shaft in 4th.
0.929 x 3.75 turns of the input shaft = 1 rotation of the output shaft in 4th.

The pinion gear is smaller than the ring gear, so it will have to turn more times to spin the ring gear a full rotation.
if its got an open diff you will need to make sure that both left and right output flanges rotate equally, so you will need to mark both of them and make sure they stay in alignment. If it's got an LSD it's probably not going to free wheel and just spin one output shaft, but still worth watching to make sure it doesn't happen.

Right...the ring & pinion is a gear reduction.

 

[Ryan L]

as a team we are getting there.

 

[Neil]

as a team we are getting there.

 

[Randy Folsom]

0.929 x 3.5 turns of the input shaft = 1 rotation of the output shaft in 4th.
0.929 x 3.75 turns of the input shaft = 1 rotation of the output shaft in 4th.

The pinion gear is smaller than the ring gear, so it will have to turn more times to spin the ring gear a full rotation.
if its got an open diff you will need to make sure that both left and right output flanges rotate equally, so you will need to mark both of them and make sure they stay in alignment. If it's got an LSD it's probably not going to free wheel and just spin one output shaft, but still worth watching to make sure it doesn't happen.

Quaife uses an ATB differential. I have no idea how the flanges will rotate in response to the input shaft rotation. I will find out when I get back home next week.

Trust the Quaife ATB Differential – The Choice of the OEM - Quaife

Imitation may be the sincerest form of flattery, but many are counting the cost of buying cheap imitations of the Quaife ATB Differential!

www.quaife.co.uk

 

[Howard Jones]

Sorry for the error but you get the idea.

 

[JP Verweij]

Quaife ATB acts like a normal open diff when not locked. It works better on tarmac then off road.

 

[Randy Folsom]

Quaife ATB acts like a normal open diff when not locked. It works better on tarmac then off road.

JP, Does that mean that when I turn the input shaft while in gear (sitting in the crate), that only one side will rotate, and that one side will turn per the gear selected and final drive ratio? Currently the box is in neutral. How do I get to go into gear? I don’t have any linkage yet. I also have not put any oil in yet. Cheers, Randy

 

[JP Verweij]

Open diff, when turning input shaft one wheel will turn front, one wheel will turn oposide.
Plate LSD, both will turn same direction.

No matter what diff, a turn input is a turn somewhere else in the driveline.