Quarter Master HD gear drive twin disc

[kilo4]

Since my tranny was out for replacement. I've decided to upgrade my Quarter Master twins to the new HD gear drive street version. I ran in to a few problems but it all worked out in the end thanks to twicks69.

At first, the disc I received was damaged from Quarter Master, it was packed loose inside the box. It took almost 3 weeks for Quarter Master to send a replacement.

I received the replacement disc two weeks ago and finaly installed it last week. The procedure went great, I tripple checked everything and the installation was perfect.

The initial start was a disaster, smoke was coming out of the tranny. As it it turns out my throw out bearing sleeve was making contact with the gear drive hub. It melted a small part of the throw out bearing sleeve and destroyed the bearing itself. Luckily with guidance from twicks69, I was able to clean off the damage and properly cleared the tranny for the gear drive hub. The problem was either my clutch assembly stuck out more than normal or Quarter Master did not machine the hubs enough to allow clearance.

For those who want to see numbers:
- throw out bearing sleeve lenght = 1.61
- I cleaned and filed my sleeve to = 1.462

Tools used:
- 6" double bastard file
- Coke can cut to 2" strip to protect the shaft while filing
- 300 grit sand paper
- digital caliper

I installed the tranny and removed the upper throw out bearing rubber vent tube to get a visual clearance. It cleared the gear drive hubs nicely, and finished the rest of the installation.

FYI
You shouldn't have to clear the throw out bearing sleeve because the gear drive hub itself should come already pre-cleared.

Feedback
Pros:
1. The clutch is soft like a stock clutch
2. It's rated to hold 700 ft lbs.
3. almost no clutch chatter unlike older version
4. very smooth engagement
5. very nice twin disc engagement/disengagement
6. easy stop and go traffic


Cons:
1. still has a soft mild squeel during intial engagement on 1st and Rev
2. my clearance issues
3. QM customer service not the fastest nor the best

I'm very happy with this clutch and cant wait to take it to the track this summer. I would like to thank twicks69 again for an outstanding support.

[twicks69]

Nice writeup Alvin, I will deal with QM to make sure this doesn't happen again.

The gear drive clutch disks Alvin is using are the newest variation of the gear drive hub disks with a cerametallic friction material, otherwise known as the "street version" Gear Drive HD Disks. This clutch friction was initially designed for the Quarter Master prototype Evo Gear Drive Modular Clutch that I had a a small hand in helping design. The street friction gear drive disks are very smooth for daily usage with a longer wear life than the race version at the cost of a lower torque capacity. The torque capacity is rated at 700 ft/lbs while the race version ferrometallic disks are conservatively rated at 800 ft/lbs and are a bit harsher but better for heat dissipation in racing.

The Gear Drive hub utilized on this disk was originally designed for the 4G63 for use in my car after I had a few regular hub failures. This style hub has substantially better engagement of splines on the input shaft and the disks preventing hub failure while giving better clutch modulation and better engagement characteristics.

[kilo4]

If anybody is interested in purchasing a gear drive set. I suggest purchasing them
from TMZperformance. If you run into issues like myself, you'll have inputs from Tim the guy that help design the hub. Thanks Again Tim for the awesome clutch!

[twicks69]

As for the reason for his input shaft sleeve damage, Quarter Master had a batch of disk packs made with the wrong hub and offset dimensions which ended up with the hub too close to the input shaft sleeve. These problems have been remedied by Quarter Master and I have been in close contact with them regarding it since they are running the dimensions I give them for this disk design. I just pulled my transmission to confirm dimensions for them using my own clutch and their numbers were WAY OFF resulting in the disk hub to be around 0.240" offset too far towards the input shaft sleeve causing damage, disenegagement issues, and overall major headaches. As I previously mentioned, these problems have been fixed as of 07/12/2011.

If you have problems with your clutch and the gear drive hubs, please contact Quarter Master Clutch directly, their contact information is on their website at Quarter Master® Home page.

Thanks!