Hello All,
Over the past 2 races I detonated the 4th gear dog ring. That's taken out 2 input shafts, 2 drive gear sets, and of course 2 dog rings. At any rate, I doing my latest rebuild and found about 0.004 of play between the dog ring and gear. Has anyone blown up a dog ring? Do you know if play between the dog ring is OK? Have replaced the pilot bushing and re-dialed in the bell housing over the last weekend, but I'm being cautious. I did speak with Jerico and they tell me that some play is OK, but did not give me a hard number. So, a 2nd opinion would be much appreciated.
Thanks
Greg

Hi Greg,
Sorry about the damage in your Jerico, and sorry I don’t have an answer for you now. My trans is out of my car right now and in storage (i have my street 5 speed in now). When I get a chance, I will try and drag it out and pull top cover off and measure it for you. You’re talking about the clearance between the sides of the main gear and dog gear after it’s shifted over? I know you can’t mean the backlash because there are miles of clearance there.
Also, how many runs do you have on your Jerico? I believe you run an adj slipper clutch?

Greg D

Hi Greg,
Thanks, yes, the distance between the side of the main drive pinion and the front side of the dog ring. I put a 0.1mm shim between the front snap ring and the bearing and it get rid of the slop. I just can' imagine there should be much gap since it allows the dog ring to kind of tilt. There's probably about 300 passes on this trans and yes, slipper clutch. My last Jerico lasted me about 2000 passes before it grenaded and I but it used.

Ok…I understand now. As far as I know, I shoukd be able to get to it tomorrow after work and check for you. I will measure it and report back to you. But, regardless of what the gap is, the only way to minimize it more or eliminate it woukd be to install a shim in front of the main gear to move it rearward. Correct? That’s what I’m thinking.

The shim actually works behind the front snap ring to pull the shaft forward to take up the play. I only had a 40 mm id shim that would not go over the splines. I had to get a 50mm id shim. And yes, it is better just in front of the dog ring which I can now do. I was concerned about expansion from heat and putting too much stress on the snap ring behind the dog ring. I know there is still a slight amount of play but it's smaller than I can measure in situ. I don't want to pull this thing completely apart for a 3rd time in 3 weeks
And thank you!

Time to sell it, and buy a G Force 101A...

I dragged my Jerico out today after work and checked the gap for you Greg. Mine is set at .009”
This tranny only has about 70 track passes on it since new. Never been apart. Snapped a few pics for you. Hope this helps.

You are a saint! Thank you.
It still looks great in there. That's great, it looks like I don't have to worry about that. That leaves the stop adjustment on the shifter. I did find the three 3/8" bolts that mount the shifter to the mounting plate, bent. I guess I'm pulling to hard. That would change the adjustment of the stops some. I did adjust before the last failure, but maybe not enough. I'll take the shim out and hopefully report on Sunday.
Thanks again!

Man that box looks great inside , hard to believe there is 70 passes on that thing. You must have perfect timing on you right hand and left foot

Gus

You’re welcome Greg. Glad it helped.

Thank you Fourgear……but my “Long” H shifter plus the wide open spaces on the dog gear make shifting this tranny almost effortless.

Just as an update, into second round on Sat and did not scatter. Although I did take a snoozer. Four passes is not enough to give me a bunch of confidence. The last new dog ring lasted 4 passes (left). I did install an old 'high strength' webbed dog ring. It has a little bit of wear, but figured it was better to possibly miss a gear than break it. It's interesting, but Jerico told me that version is not available and that they gave up on them a couple of years ago. I find that strange. Greg's DR4 above has them.

I have a Long H-pattern shifter for my Richmond but I've never tried it yet. My 5 speed is face-plated so it will probably shift good too. I still use a Long V-gate on it when I race it.

Gus

What Jerico told you could be true……i bought mine in 2008. It waa many years before I got it installed and Racing with it. And I don’t get out more than a handful of times per year , unfortunately. Hoping that will change.
Glad you trsns held up for you so far , Greg.