WTB: Mk 9 dog rings...

[fshort]

Hi all:

Because I seemingly have forgotten how to shift since I last drove my Tiga in 1983, I need at least (2) serviceable dog rings.

As a bad shifter & a cheap one too (what a combo!), brand new/near perfect parts are right out!

Something that will last me more than 1 or 2 sessions, please.

I'm in Sequim, WA 98382 if that matters.

Thanks!

Regards,
James

[DaveW]

They may need replacing. When they get too worn, they allow the finger to tilt, screwing up, or even preventing, shifting.

[fshort]

They may need replacing. When they get too worn, they allow the finger to tilt, screwing up, or even preventing, shifting.

Hi Dave:

Thanks for the tip!

While I would jump (leap!) to blame the machine, Tracy Dye recased my gearbox during the 40-year frame-up, because of case cracks. He handled setting the forks, checking the gear stack-up, the CWP set-up, etc., doing an excellent job.

It's all me, unfortunately... I'm not really matching speeds well enough on downshifts and just being rough in general. I just need to relax and not try so hard.

After 2 seasons in the 1980s, I was a mid-packer (in 45 car fields) - now I'm just slow.

It's frustrating.

Regards,
James

[DaveW]

...It's all me, unfortunately... I'm not really matching speeds well enough on downshifts and just being rough in general. I just need to relax and not try so hard.

After 2 seasons in the 1980s, I was a mid-packer (in 45 car fields) - now I'm just slow.

It's frustrating.

Regards,
James

You might try using the clutch on downshifts. I know most guys who really shift well never use the clutch except to start or in the paddock, but I use the clutch on every shift (except in 2019 when I ran Steve Jenks' MZR which was sequential).

You may find that using the clutch, at least on on downshifts, makes shifting easier, smoother, and prolongs the dogs' lives. One does have to set up the MC size so that using the clutch is effortless. Many cars have too large a MC (3/4 v 5/8) which makes clutching difficult. One does not have to disengage it completely on each shift, since just a slight slippage smooths thing enormously.

I never could master shifting clutchless to my satisfaction (I have a lot of mechanical sympathy), so I gave up after trying it multiple times with mediocre results. If done correctly, using the clutch either up or down will not slow you down, and at least for downshifts may make you smoother and faster.

[fshort]

You might try using the clutch on downshifts. I know most guys who really shift well never use the clutch except to start or in the paddock, but I use the clutch on every shift (except in 2019 when I ran Steve Jenks' MZR which was sequential).

You may find that using the clutch, at least on on downshifts, makes shifting easier, smoother, and prolongs the dogs' lives. One does have to set up the MC size so that using the clutch is effortless. Many cars have too large a MC (3/4 v 5/8) which makes clutching difficult.

I never could master shifting clutchless to my satisfaction (I have a lot of mechanical sympathy), so I gave up after trying it multiple times with mediocre results. If done correctly, using the clutch will not slow you down.

Hi Dave:

Thanks for this info. I always use the clutch, even on upshifts(!). I know I don't need it for upshifts - but I'm needing to relearn how to drive...

In the past, I would always jump on the linkage, if presented with all this dog wear on a customer car.

But, during my 40-year frame-up, I ground off the cheap junk U-joints Tiga brazed on the shift linkage & replaced them with MS U-joints, with saddle washers, AN bolts, etc. I then narrow-gated the gearbox and paid particular attention to clearances & fits of the linkage. So I don't think its the linkage.

Mark D. has suggested that I check the shift fork groove clearances to the dog rings - which I will.

What's really frustrating, is that 40 years ago (with this car), I don't remember any shift issues - and I looked at my old invoices and I didn't burn thru dog rings like this.

Thanks again!

Regards,
James

[DaveW]

delete

[DaveW]

...What's really frustrating, is that 40 years ago (with this car), I don't remember any shift issues - and I looked at my old invoices and I didn't burn thru dog rings like this.

Thanks again!

Regards,
James[/COLOR]

You might check your dog rings for the width of the dogs compared to the gaps in between - the wider the dogs and the smaller the gap, the harder it is to get clean engagement. Old dog rings and gears had wider dogs. Modern parts have much higher gap to width ratio, and that will make a noticeable improvement.

Also if the gear spacing along the shaft is off with regard to the dog rings due to not correct spacer width, etc., that will cause shifting difficulties.

[rdracr]

Don't forget to check the linkage joints. They can be beat sloppy if not there already.

[Gary Godula]

So is there anyone who regrinds dog rings to reface the dogs so that they engage the gear properly, or is there no way to heat treat/surface treat the dogs after grinding? It would probably be a good business if it were possible and financially feasible.

[Ian Jenkins]

So is there anyone who regrinds dog rings to reface the dogs so that they engage the gear properly, or is there no way to heat treat/surface treat the dogs after grinding? It would probably be a good business if it were possible and financially feasible.

Jamie Housman machined some for me a few years back. Price seemed reasonable and he was up front about those that were too far gone to be saved.

Jamie Houseman
Houseman Autosport.
www.racegearbox.com
519-652-3030

Not sure if Scotty will machine used rings but he might sell new ones if you can't source them from the usual places. Nice guy and I was happy with his work.

https://www.sy-gearboxes.com/

[bob darcey]

I've got two FF's, one with narrow dogs and the other with wide--- can barely shift the one with wide dogs. PITA.
Just got off the phone with Wayne Mitchell, dogrings.com, 760-942-9170. $125.00 ea shipped, a better deal than buying someone's old stuff.

[fshort]

Hi all:

Here's a summary of the good tips & ideas I've received:

1) Check shift finger bushings in bearing carrier for wear.

2) Minimize using the clutch on downshifts, never on up-shifts.

3) Check the shift fork groove clearances to the dog rings.

4) Use modern dog rings w/ wider gaps.

5) Verify gear spacing along the shaft is correct.

6) Check linkage U-joints for wear.

7) Shift slowly & smoothly, then fast & smoothly, & match revs on downshifts.

Vendors:

1) Jamie Houseman
Houseman Autosport
www.racegearbox.com
519-652-3030
Re-machining gear dogs: $75.00 USD
Re-machining dog rings: $125.00 USD
Regrinding used dog rings/gears

2) Wayne Mitchell
dogrings.com
760-942-9170
$100.00 ea
New dog rings

3) Scotty
https://www.sy-gearboxes.com/
New dog rings

Also, I don't have a bead seat yet - just padding, so I think being slotted in better to the car will help...

I'll try all these things - the car snicks thru the gears on the stands (engine running) as it should..

Thanks again!

Regards,
James

[scorp997]

FWIW, Wayne’s website shows Mk dog rings at $100..... (just saw you list them as “shipped”)

dont use the clutch on upshifts (ever if possible) and learn to downshift without.. doesn’t take long to get it right and it is much quicker as well.

[Hawke]

FWIW, Wayne’s website shows Mk dog rings at $100..... (just saw you list them as “shipped”)

dont use the clutch on upshifts (ever if possible) and learn to downshift without.. doesn’t take long to get it right and it is much quicker as well.

And Hewland recommends that you should not use the clutch for any gear change. If you change gear as recommended by them, you will have less wear on the dogs rings and gears. Go to their web site, and download their manual.

And I also vouch for the dog rings from Dogrings.com. They seem last forever. I think that the set I’m currently running is at least 5 seasons old.

[scorp997]

Copied from Hewland......

For successful gear shifting, remember that it is critical to ensure that all mechanical elements between the drivers hand and the dog faces are in good order and properly set. This includes the gear linkage in the chassis. Successful up-shifting (defined as fast and non dog-damaging) will be achieved by fully moving the dog ring as rapidly as possible from one gear to the next, preferably with the engine's driving load removed until the shift is completed. (The opposite is true of a synchromesh gearbox as used in passenger cars, where slow movement helps). It should be remembered that it is not possible to damage the dogs when fully engaged (in gear). The damage can only take place when initiating contact during a shift (the `danger zone`). Therefore this period must be made as short as possible. If a driver moves the gear lever slowly, or if the linkage is not rigid and effective, dog wear will occur. We always recommend lightweight yet solid rod linkage, as opposed to cables. We list below the different methods of up-shifting that are used in racing most commonly. These are in order of shift method preference. Automated (semi-automated): The movement of the dog ring is powered and the engine is cut / re-instated in a co-ordinated manner. Gear-shifts take milliseconds. This system produces zero dog wear when set up well, and highlights the advantages of minimising gear shift time. Manual with Engine Cut: This system is almost as good as an automated one as long as the driver pulls the lever very quickly. A `cheat` version of this is to shift on the engine rev limiter, which can work well. With this system it is especially important to move the lever as fast as possible. Otherwise the engine will be reinstated during partial dog engagement, causing damage. The damage can usually be felt by the driver. Manual: With no assistance from the engine management, the driver must lift off the throttle sufficiently to allow the dog ring to be pulled out of engagement. He should then stay off the throttle long enough to allow the dog ring to engage with the next gear. In practice, the driver can move the gear lever faster than he can move his foot off and back on to the throttle. Therefore the effective method is to apply load to the gear lever with your hand and then lift the throttle foot off and back on to the pedal as fast as physically possible. In lifting your foot, the loaded gear lever will almost involuntarily flick to the next gear before the foot is re-applied to the throttle. Another method is to load the gear lever with your hand, stay flat on the throttle and dab the clutch to release the dog ring. The overall effect on the gear shift is similar to the above method, but clutch wear may become a big issue. The worst method (most destructive and definitely slowest) is to attempt to change gear in a `passenger car / synchromesh` way, i.e. lifting off the throttle, dipping the clutch, moving the gear lever, letting the clutch up and re-instating the throttle. The method causes unnecessary clutch wear, does absolutely nothing to help come out of gear and usually causes dog wear whilst engaging the next gear. This wear is due to several reasons. Firstly, it is impossible for a driver to co-ordinate the complicated sequence of all five physical movements accurately. Consequently the engagement dogs often find themselves engaging whilst the throttle is applied. The lever is usually pulled more slowly as it was not pre-loaded, lengthening the `danger zone`. Successful down-shifting: Similar rules apply regarding speed of shift, with the unloading of the dogs obviously performed in the opposite manner. Whilst braking, the dogs must be unloaded by either touching the throttle pedal or by dipping the clutch. However, one sharp dab of clutch or throttle is appropriate per shift. Continued pressure on either will cause dog damage for different reasons. `Blipping the throttle` just before engagement is advisable if the rev drops between gears are over 1300 rpm, as this will aid engagement and stabilise the car. For ease of downshifting, make the downshifts as late as possible in your braking zone (i.e. at lower road speed), because the rev drops between each gear are then lower. So many drivers make the mistake of downshifting as soon as they begin braking, causing gearbox wear, engine damage and `disruption` to the driving wheels. For any further advice or questions, please contact our Commercial Team, who will be happy to advise.