How to keep Ring and pinions in your trans????????????????

[Muffler Mike]

Cool explanations and cool pics guys.


LOL. pass that .00000001 point and we can brake a crow bar in a sand box.

[DRAGRACR]

I have broke 2 ring and pinions the last 2 times that I have been to the track.

What R&P ratios are you using? How is the R&P lash/preload set? What's your suspension/tire setup?

3.88 R&P. I am running the back lash at 0, and I am running adjustable coil overs on the rear, and a fabbed ladder bar setup, with a 26x10.5-15 tire out back . I am running a stage 2 Kennedy with a tilton dual disc setup. I am going to put a stage 1 back in this time.

I think that I will try the stud this time going thru the case also.

[Pablo]

Bored&Stroked put it pretty well. Unless you go "all the way" and do EVERYTHING POSSIBLE to limit R&P movement, the liklihood of success is minimal. And while I would highly recommend shot-peening and then REM polishing, I would NOT recommend cryo treating case-hardened high nickel steels any more than I would recommend annealing.

[Henryhoehandle]

Photo #3 shows how a 1st gear thrust washer is mated to the flipped 4th pinion gear.

Photo #4 shows how proper clearance between thrust washers can be measured during trial pinion-only assembly.

While the heavy-duty aluminum housing shown in photo #4 is no longer available, the Autocraft aluminum intermediate housing can be modified to do the same job. Clearance can be measured through the mainshaft bearing bore during trial pinion-only assembly.

I should mention that while we experimented with a number of different taper roller bearing arrangements, we kept returning to the thrust washer method shown in the photos. The reason is that with the roller bearing, a substantial amount of installed preload is required to properly limit forward pinion movement. And yet the "problem" (forward pinion movement) only exists for a fraction of a second during launch (and perhaps a fraction of a second when power-shifting into 2nd gear). So the SUBSTANTIAL preload required on the taper roller bearing to do the job translates to unwanted turning resistance during the entire quarter mile, while the thrust washer method only increases friction for an instant. You might want to save the pics and enlarge them for more detail.

[boredandstroked]

The autocraft housings are not avaliable and VERY hard to find, but not as hard to find as the elephant housing. There is a BILLET aluminium housing avaliable that is more than up to the task. Anyone interested in one can PM me. I believe the last to were $350 a piece. They take a bit of fittment. i.e reaming the dowl and stud holes to fit the case and a little grinding to fit in a motor plate set up. They were purpose made to replace the elephant housing. Unfortunately a dildo between me and the machinist is causing a few problems, but well thats just the nature of the thing.

Gotta love that crowbar in a sandbox Mike.

[Pablo]

Our HD housing from the late '80s:
http://www.thesamba.com/vw/forum/album_ ... _id=299079

Hewland and Webster are two other possibilites for HD Type 1 housings, when boredandstroked runs out. (Although I'm not certain that the Webster version has enough meat for the reverse lever block.) Yeah, Engine Machine Service bought all my remaining stock of Elephant housings when it cured the severe issues they were having with the HARD-launching BugPack car's trannies. A long time ago --

[Carl Nolen]

Who provides the steel-sleeved service? It is something I am interested in. I normally get 140-160 runs on a 3.88 r&p using the timken bearing setup in the intermediate housing area. Seems to help the overall life of the fragle type 1 r&p. I use a stock four bolt pinion bearing case with a welded gusset. Always looking for something better for the potato chip type 1. I also use a anti-shocking devise which does help with r&p life. Instant r&p breakage is normally sudden shock from harsh clutch lock up. Does the Rhino case appear to be a better setup than the stock case? Stock gusseted case usually last about two r&p services and then bearing area worn too much. Could sleeving save these old cases? Type 1 trans life really comes down to the car(not all are the same) being in harmony with clutch, tires, and suspension all working together. Too much clutch, too much tire, too stiff suspension could cause trans trouble. Thanks, Carl.

[boredandstroked]

Carl,
Rimco does/did it. I had them do a steel sleeve about a year ago so they probably still do. It came out very nice. You need to make sure you send them a case that is in VERY good condition or the bore will not come out correctly. A case that has very little use or a new case would be your best bet. You could have any case sleeved no matter how worn but it would take a lot of set up time to get correct; probably no one is going to take the needed time so it would likely not come out well. A spankin new rhino with a welded up drain hole and a steel sleeve is probably the most for the money of anything going.

[Pablo]

While I would sleeve any new case on any dragrace trans, a worn case is also easy to set up if a new intermediate housing is used as a centering guide. (I went through some hair-pulling before this simple answer came to me.)

The length of the main case requires that you remove the long studs (leaving just the two locating dowels), so that the intermediate housing is easily removed after centering on the Bridgeport table. The table is then merely cranked upward into place for boring.

The primary reason for using a Rhino case is that the extra meat on the bottom allows the through-bolt (shown in one of the photos). No need for welded gussets (which can warp the case). If R&P are properly contained, the main case will never break.

[Carl Nolen]

Welded gusset on stock case is neccessary. I cracked several in the early days until I had that procedure done. Haven't cracked a case since. But do wear out pinion bearing area after 200-300 runs in three years of racing or so. Pablo, have you monitored these non gusset Rhino cases with steel-sleeve over time for wear and cracks in drag cars? I normally average 100 or so runs a year in a 1565(car & driver)lbs bracket car running 11.30/7.10 or so. The most runs I have got on a 3.88 was 200 a few years ago. But that was probably due to some old Firestones that slipped too much. With some new sticky 6x26 M&H's, dropped to about 140. But hey, I'll take 140 runs on a r&p. Thanks boredand stroked and pablo for your input.

[Muffler Mike]

defintly some good info guys.

[Pablo]

Yes, I have monitored the Rhinos with no gussets. Side cover lift-off and forward pinion movement "necessitate" gussets, but I'm convinced aren't necessary if the R&P is set up exactly as described above.

Our own 9.30's car was pretty hard on parts, but we never broke a case and never lost an R&P. Yes, cracks develop over time. (Just so much can be expected from the dinky Type I.) But it takes a while for cracks to develop to the point of catastrophic failure. Exactly "how long" is something I never documented, as my conservative nature had me pulling the R&P at the first sign of cracking. But seeing many stages of crack growth, I know that there are a lot of cracked pinions running out there ---

Thanks for the input on your number of runs on the 3.88, Carl. I hate to claim hundreds of passes, as I always get some bozo arguing that I'm full of sh**. Nice to have some back up ---

Don't get me wrong --- I'm not saying that going to a Type II is a bad idea, only that the Type I is a lot stronger than most believe. However, I always did exactly the same for forward pinion movement in the Type II (using an aluminum Berg intermediate housing) and would see those guys easily go a full season before inspection. Offroad 091 transmission got the small Timken bearing set-up, a sandwiched steel plate between bellhousing and main case, and of course our chromoly pinion nut ---

[boredandstroked]

Thanks for the input on your number of runs on the 3.88, Carl. I hate to claim hundreds of passes, as I always get some bozo arguing that I'm full of sh**. Nice to have some back up ---

2 years or so ago I would have been that bozo. Carl is getting great R&P life considering his et and weight. Maybe he is just lucky but he obviously has something correct. Carl also gave a lot of input when I was looking for the correct approach so here's a public thank you Carl, and to you Mike and agian to you "Pablo". I am going to get mid-evil on the tranny this weekend and will hopefully be smiling at the end of the day. I'm looking for mid 1.3 60's and a 6.5x with the same ol 1800 lbs with my Frey Racing engines collaborated ALL MOTOR power plant. Thats gonna be a tall order for any potato chip...

[Pablo]

Too much clutch, improper launch technique, too many burnouts, too little tire pressure, etc can all contribute to excessive strain on R&P. Most of those areas were covered by my partner, so I'm not the guy to ask. But I do know that our slicks would make a half-rotation before hooking --- and that was a good thing.

Our clutch was "just enough" to do the job (prior to the days of VW multi disc). I was always careful to properly preload the geartrain. And if by chance I experienced a bit of wheelhop (not very often), I got into the trans immediately to see what was tweaked before it "let loose for good".

[Scott Gilbert]

This is a great thread. Just awesome information. After reading everything I’m very interested in the pinion thrust washer idea. So, I’ve got a few questions. Why must an aftermarket intermediate housing be used? Is the stock housing not able to take a thrust load? Is a different bearing required? Will the bearing walk out? On the last tranny I built I used a Weddle bearing retainer plate sandwiched between the intermediate and nosecone to avoid forward bearing movement. I checked on prices for the Hewland ($1400) and the Webster ($620) intermediate housings and they are expensive.