Gearbox refurbished & Clutch replacement
The clutch was slipping. This unit was from my tin top Mk1 Golf; the clutch was over ten years old. There was also a leak from the drive flanges. It was definitely time for a refurb.
Once I got the box off, I found the input shaft seal had gone on the gearbox, and the crank seal on the engine was leaking.
I had two gearboxes for my Tin Top Golf. I used the close-ratio gears from my 1.6 and the case and lower-ratio final drive from a newer, stronger TD box and installed a Quaife LSD.
The advantages of a Quaife LSD are detailed here.
Details of the gearboxes used are below:
Code 1st. 2nd. 3rd. 4th. 5th. Ring & Pinon
FM,FD,FK 3.45 2.12 1.44 1.13 0.91 3.89
Notes - Close Ratio 1.6 GTi - These are the gears that were used
Code 1st. 2nd. 3rd. 4th. 5th. Ring & Pinon
ATH 3.45 1.94 1.28 0.91 0.75 3.67
Notes - From '93 1.9 TD 75hp - This is the case and final drive that was used
With the combination, the ratios are:
1st. 2nd. 3rd. 4th. 5th. R&P
3.45 2.12 1.44 1.13 0.91. 3.67
Based on the ATH Case and final drive (R&P) with a close ratio Golf Mk1 1.6 GTi gears and 16" wheels with 40 profile tires, the MPH speeds in each gear should be:
1st. 2nd. 3rd. 4th. 5th.
38 62 91 116 144
Rev limiter set to - soft limit at 7600 hard limit at 7800
This setup feels really nice in the soft top with 30mph in 5th sitting at under 2000 rpm
The gearbox was refurbished by Stephen A Brear Gearboxes Ltd in Leeds. The 2nd & 3rd synchros and the input oil seal and drive flange seals were replaced. The clutch rod bush and seal were also replaced along with the detent mechanism (gear selector mech)
With the box off, I replaced the sump gasket & gearbox crank seal.
I sourced a Sachs Reinforced Clutch Plate and a Helix Autosport organic clutch plate with a lightened and balanced flywheel. Together, the max torque the setup can handle is 250nm, which is adequate as the engine pushes out less than 200nm
The setup with the Sachs clutch plate - 883082.999616 has been on my wishlist for a while, so finding a used item with a lightened and balanced flywheel and a clutch plate was a result 😍
Before fitting the lightened flywheel, I read up on the pros and cons; honestly, I did not notice any of the cons, like car staling and erratic idling. The car revs a bit quicker, feels smoother through the rev range, and starts up a tad faster.
n While fitting the gearbox, I took the opportunity to replace the majority of the transmission linkage parts, which I sourced from Classic VW
The following parts were replaced:
A Techtonics Tunning short shift kit and a TSR G01 Spherical Gear Linkage kit were installed.
These kits used to be easily sourced in the UK back in 2010. However, now they are impossible to find. They are available in good old USA from UA-Rally-Team Short Sift Kit. They have videos explaining the benefits of not fishing for gears with a sloppy gear stick.
Getting the alignment is a right pain in the ass, as even with a helper and you under the car, it is impossible to get the feel that you're happy with as it comes down to personal choice. I ended up watching this video Golf Mk1 Shifter Linkage Tuning, and I got everything lined up and then made small adjustments to the adjustable links until I was happy.
