angel
Enthusiast
- Messages
- 2,444
- Location
- Athens, Greece
Inspired by Domsky - in fact learning from him that such a part exists - I set about getting one in order to make the R4 even more off road worthy. I contacted Quaife directly and they informed me I had to buy it directly from Gekkoil, a Belgian company specializing in raid equipment. Gekkoil receives small batches of differentials from Quaife 2-3 times each year, depending on request. So I asked for availability, end of 2019, and waited for a response from them when the next batch would be expected.
I didn't have any news from them for some time, then the Covid situation broke out and everything went out of schedule. But in summer 2021 I started thinking again about the Quaife. I had just bought a 1984 GTL as a temporary replacement until I make the Jogging roadworthy again, and had a 5TS gearbox with 3,62:1 final drive lying around, and was thinking that this would be the best combination for both off roading and motorway cruising. So I emailed Gekkoil again - November 2021 - and they let me know that the Quafe was always available and the new batch would be available in 10 weeks. So I paid the sum - half a car, hoping it would be worth it! - and waited.
In December 2021 an email from Gekkoil let me know that my differential arrived and they were soon to dispatch it. What a surprise, almost four months earlier than expected! But after some days of watching the parcel being stuck in Germany, I contacted both UPS and Gekkoil and after many emails, they conclyded that the pacel had been lost. I had no other option than wait for Gekkoil to get insurance compensation from UPS and send another differential. Finally, in early April, it arrived.
Tiny, it fits in the palm of a hand!
I had already removed the differential of the 5TS gearbox so I fitted the crownwheel on the Quaife.
New differential bearings
I choosed to follow Gekkoil's suggestion of tightening the differential bearing carriers to the point of zero play, then one notch further in order to set bearing preload. Otherwise i would have to strip the gearbox to remove the secondary shaft / pinion in order to correctly measure differential starting torque.
I then set crownwheel/pinion backlash as per the manual (0,12-0,25mm - I set it to 0,20mm for better lubrication of crownwheel teeth).
The rest was a matter of removing the gearbox of the GTL and fitting its bellhousing and primary shaft to the 5TS one (10mm shorter on the R4), and refitting the unit to the car.
Testing the car on city roads revealed no surprise, except for the fact that steering becomes cosiderably heavier when you enter a curve pressing on the accelerator. The moment you lift off, it becomes instantly light. You can also feel it when accelerating at a straight line, it's a self centering effect like having too much castor at the wheels.
I headed towards Penteli mountain, on an uphill forest road I failed to climb three times in the past. Well this time I almost didn't notice I made it! Road surface was badly eroded from winter's rain and snowfalls, but the GTL never lost traction. Climbing further upwards, there was a very tight hairpin where friends with Cherokees had to shift to low range in order to get past it. It was only then when I felt some wheel spinning, but the car regained traction almost instantly and proceeded. With a conventional differential I would go as far uphill as the tyres (Fedima off road ones) allowed, then a wheel would suddenly break loose and the car would get stuck in the middle of an uphill. Now I simply chose the line and pressed the accelerator. Amazing! There was a point where the engine stalled at the middle of a rutted, steep uphill, probably because fuel in the float chamber foamed from all that sloshing around. I stopped, started the engine again then pulled away like driving on tarmac. Really impressive.
Having done the first testing, I decided to return by taking the same route. What a surprise...I had to check the GPS twich to make sure I was following the correct route, I couldn't believe I had climbed all that stuff!
I didn't have any news from them for some time, then the Covid situation broke out and everything went out of schedule. But in summer 2021 I started thinking again about the Quaife. I had just bought a 1984 GTL as a temporary replacement until I make the Jogging roadworthy again, and had a 5TS gearbox with 3,62:1 final drive lying around, and was thinking that this would be the best combination for both off roading and motorway cruising. So I emailed Gekkoil again - November 2021 - and they let me know that the Quafe was always available and the new batch would be available in 10 weeks. So I paid the sum - half a car, hoping it would be worth it! - and waited.
In December 2021 an email from Gekkoil let me know that my differential arrived and they were soon to dispatch it. What a surprise, almost four months earlier than expected! But after some days of watching the parcel being stuck in Germany, I contacted both UPS and Gekkoil and after many emails, they conclyded that the pacel had been lost. I had no other option than wait for Gekkoil to get insurance compensation from UPS and send another differential. Finally, in early April, it arrived.
Tiny, it fits in the palm of a hand!
I had already removed the differential of the 5TS gearbox so I fitted the crownwheel on the Quaife.
New differential bearings
I choosed to follow Gekkoil's suggestion of tightening the differential bearing carriers to the point of zero play, then one notch further in order to set bearing preload. Otherwise i would have to strip the gearbox to remove the secondary shaft / pinion in order to correctly measure differential starting torque.
I then set crownwheel/pinion backlash as per the manual (0,12-0,25mm - I set it to 0,20mm for better lubrication of crownwheel teeth).
The rest was a matter of removing the gearbox of the GTL and fitting its bellhousing and primary shaft to the 5TS one (10mm shorter on the R4), and refitting the unit to the car.
Testing the car on city roads revealed no surprise, except for the fact that steering becomes cosiderably heavier when you enter a curve pressing on the accelerator. The moment you lift off, it becomes instantly light. You can also feel it when accelerating at a straight line, it's a self centering effect like having too much castor at the wheels.
I headed towards Penteli mountain, on an uphill forest road I failed to climb three times in the past. Well this time I almost didn't notice I made it! Road surface was badly eroded from winter's rain and snowfalls, but the GTL never lost traction. Climbing further upwards, there was a very tight hairpin where friends with Cherokees had to shift to low range in order to get past it. It was only then when I felt some wheel spinning, but the car regained traction almost instantly and proceeded. With a conventional differential I would go as far uphill as the tyres (Fedima off road ones) allowed, then a wheel would suddenly break loose and the car would get stuck in the middle of an uphill. Now I simply chose the line and pressed the accelerator. Amazing! There was a point where the engine stalled at the middle of a rutted, steep uphill, probably because fuel in the float chamber foamed from all that sloshing around. I stopped, started the engine again then pulled away like driving on tarmac. Really impressive.
Having done the first testing, I decided to return by taking the same route. What a surprise...I had to check the GPS twich to make sure I was following the correct route, I couldn't believe I had climbed all that stuff!
