Author |
Message |
vwracerdave Samba Member
Joined: November 11, 2004 Posts: 15303 Location: Deep in the 405
|
Posted: Mon Apr 12, 2021 11:01 am Post subject: Broken IRS end gears. |
|
|
1900 Lb. Ghia with 160 HP 2165cc and slicks..
Last year I had an IRS transaxle built with a Super Diff. I made 13 passes and broke the splines off the long end gear launching at the line. I simply took it apart and replaced it with another used end gear and thrust washer. It broke again after 8 passes, same exact thing broke the splines off the end that the CV flange goes on. I have over 150 passes on this Ghia with a bigger 170 HP 2276cc and never broke the end gear.
Is there any shimming or end play measurements that I missed? Is this a common weak link that breaks and is simply not strong enough for drag racing? Could this be from a Super Diff that was not machined correctly?
Many years ago I got a transaxle with "super splines" and it only lasted 9 passes before the welded splice broke. I was told they are NLA and replaced it with a stock type I end gears and it's still working today. I'm aware of the Folks diff with 091 end gears but that's a $1200 upgrade and I'm running a SSC case. _________________ 2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63
Watch my racing video's http://www.youtube.com/user/okvwracer/videos |
|
Back to top |
|
|
madmike Samba Member
Joined: July 11, 2005 Posts: 5292 Location: Atlanta,Michigan
|
Posted: Mon Apr 12, 2021 11:31 am Post subject: Re: Broken IRS end gears. |
|
|
Add H.P seem to work for the 2276 ,,Or
Quit launching so hard and add a Turbo ,,, same E.T's
sounds like the super diff housing is 'off' ? _________________ 'Black Ice'Drag Buggy 'Turbo'
Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works" |
|
Back to top |
|
|
Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1660 Location: Marshallville Ohio
|
Posted: Mon Apr 12, 2021 12:55 pm Post subject: Re: Broken IRS end gears. |
|
|
OK, there is a big difference in strenth between the 11/17 tooth spider/side gear, compared to the later model 10/15 tooth spider/gear diffs.
The 10/15tooth setup has better "lead out" on the splines that help prevent breakage.
HOwever, even with the 10/15tooth upgrade, it will be the weakest link you have.
The permanent fix is:
(NLA) super splines. They used 15tooth side gears with 091 output splines. NO longer available as far as I know.
091 diff. Weddle makes a Type 1 diff that accepts 091 spiders and gears. This is the best of the best for open (affordable) diffs.
Peloquin. Money is no object. I would say they are un-breakable, but a member here broke one... |
|
Back to top |
|
|
[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
|
Posted: Mon Apr 12, 2021 2:20 pm Post subject: Re: Broken IRS end gears. |
|
|
Ohio Tom wrote: |
OK, there is a big difference in strenth between the 11/17 tooth spider/side gear, compared to the later model 10/15 tooth spider/gear diffs.
The 10/15tooth setup has better "lead out" on the splines that help prevent breakage.
HOwever, even with the 10/15tooth upgrade, it will be the weakest link you have.
The permanent fix is:
(NLA) super splines. They used 15tooth side gears with 091 output splines. NO longer available as far as I know.
091 diff. Weddle makes a Type 1 diff that accepts 091 spiders and gears. This is the best of the best for open (affordable) diffs.
Peloquin. Money is no object. I would say they are un-breakable, but a member here broke one... |
Tom covered it anymore for an IRS if you have passed the threshold of the standard Type 1 splined outdrive.
I would think that the trans builder would have used the 15 tooth outdrives in both, but it’s something to check.
You must have got a bum Superspline outdrive. I’ve known more than a few to put 300+hp through them without issues. I had amultiple ads looking for Super Splines for 5 years before Dave/Eric’s 091 internal existed only to find two pair, so they are definitely non-existent.
I know of one builder that has bored the carrier bearing race location larger on a single side cover case to install the 091 internal diff, but most that deep are using the dsc Rhino case. 091 outdives/spiders are pretty hefty, and with their popularity presently, I can see there being components available for a while. For a street/track car that doesn’t need any type of tbd/lsd, this is the way to go imo.
The Peloquine/Quaife diffs with the 091 outdrives can be installed into ssc cases. I would think they should last hundreds of passes in something less than 2000lbs./200hp. I’m contimplating a Peloquin diff in a ssc case for the next build on the Superbeetle.
Here’s a pic of a 17 tooth outdrive compared to a 15 tooth one. The 17 tooth has an undercut where the splines end that breaks, where as the 15 tooth has the splines simply cut onto a continuous diameter section.
|
|
Back to top |
|
|
vwracerdave Samba Member
Joined: November 11, 2004 Posts: 15303 Location: Deep in the 405
|
Posted: Mon Apr 12, 2021 3:02 pm Post subject: Re: Broken IRS end gears. |
|
|
I do have the 10/15 spiders & gears.
Weddle list the Peloquine as 'out of stock'.
Is there any possibility the R&P gear depth and backlash were not set up correctly causing the extra stress on the end gear gear splines?
gkeeton, you said in your book about using 2 thrust washers on the short side end gear. I broke the long side as that is the torque side.
It was a lot simpler to repair when I was breaking type I CV joints. Now that I've upgraded to Bus/Thing CV's and axles I guess the side gears are the next weak link. _________________ 2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63
Watch my racing video's http://www.youtube.com/user/okvwracer/videos |
|
Back to top |
|
|
[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
|
Posted: Mon Apr 12, 2021 3:19 pm Post subject: Re: Broken IRS end gears. |
|
|
vwracerdave wrote: |
I do have the 10/15 spiders & gears.
Weddle list the Peloquine as 'out of stock'.
Is there any possibility the R&P gear depth and backlash were not set up correctly causing the extra stress on the end gear gear splines?
gkeeton, you said in your book about using 2 thrust washers on the short side end gear. I broke the long side as that is the torque side.
It was a lot simpler to repair when I was breaking type I CV joints. Now that I've upgraded to Bus/Thing CV's and axles I guess the side gears are the next weak link. |
The bigger CV’s is what’s creating the added stress, and showing the next weak link. I’ve mentioned about multiple thrust washers here, but maybe you are thinking of Casting Timmy in the way of a book/manual. Endplay of the outdrives imo plays more into the life of the gear teeth, but having the shafts pop in/out with excessive endplay could contribute. I’ve seen diffs that were on the loose side with one thrust washer, but too tight with two where the housing/side cover needed turned down for extra clearance. I wouldn’t go any tighter than .005 endplay so that the diff gears still have room for oil in between them.
Maybe place a wanted ad here, on some of the FB groups, and even contact Peloquin for a diff if you’re thinking of going that route. You’ve got me now thinking about finding one. The 113 pinion bearings were nla for over a year before they finally started back up production. |
|
Back to top |
|
|
Pruneman99 Samba Member
Joined: February 22, 2012 Posts: 5013 Location: Oceanside
|
Posted: Mon Apr 12, 2021 4:20 pm Post subject: Re: Broken IRS end gears. |
|
|
Are you running your slicks really soft? |
|
Back to top |
|
|
mcmscott Samba Member
Joined: March 12, 2010 Posts: 4856 Location: sanger ca
|
Posted: Mon Apr 12, 2021 4:25 pm Post subject: Re: Broken IRS end gears. |
|
|
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. _________________ There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
|
Back to top |
|
|
mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
|
Posted: Mon Apr 12, 2021 4:38 pm Post subject: Re: Broken IRS end gears. |
|
|
you sure the cv is assembled correctly.....it can be assembled correctly and swivel and incorectly and not swivel...Im sure you have checked thel real well but it may be worth taking that side totaly appart..if you dodnt asemble them it may have a wonkey ball or somethen. if all else fails...soften up the lunch. and be sure all mounts are good as well as frame hornes and that nothing is twisting at launch.as well as the dog leg& bushings. |
|
Back to top |
|
|
vwracerdave Samba Member
Joined: November 11, 2004 Posts: 15303 Location: Deep in the 405
|
Posted: Mon Apr 12, 2021 4:41 pm Post subject: Re: Broken IRS end gears. |
|
|
I run 20 PSI in the 26X6 slicks.
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
I broke the end gear on the launch as the clutch was released. Car didn't move 2-3 feet. Ghia will normally wheelie with the front wheels barley 2"-3" off the ground.
I never thought to consider that. A few years ago I did replace the spring plate urathane grommets and trailing arm bushings.. Trans has solid mounts and I'm also running a Berg traction bar. I guess I'll have to check out the shocks. Thanks.
I've put maybe 300 street miles on this trans and have had no problems driving. _________________ 2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63
Watch my racing video's http://www.youtube.com/user/okvwracer/videos |
|
Back to top |
|
|
[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
|
Posted: Mon Apr 12, 2021 5:47 pm Post subject: Re: Broken IRS end gears. |
|
|
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
What would be a good way to confirm it, then confirm you got rid of it? Gopro on the starting line? |
|
Back to top |
|
|
67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9762 Location: Oregon
|
Posted: Mon Apr 12, 2021 5:51 pm Post subject: Re: Broken IRS end gears. |
|
|
[email protected] wrote: |
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
What would be a good way to confirm it, then confirm you got rid of it? Gopro on the starting line? |
That would make the most sense. Watch the vid after the run and confirm if there is wheel hop. _________________ I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo! |
|
Back to top |
|
|
Pruneman99 Samba Member
Joined: February 22, 2012 Posts: 5013 Location: Oceanside
|
Posted: Mon Apr 12, 2021 5:52 pm Post subject: Re: Broken IRS end gears. |
|
|
[email protected] wrote: |
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
What would be a good way to confirm it, then confirm you got rid of it? Gopro on the starting line? |
I was thinking the same thing. Check everything for worn bushings/tightness. Add some air, and video the launch in slo-mo. See if you can figure out if you're hopping and shock loading.
Breaking shit sucks. Hope you can figure out what's going on. |
|
Back to top |
|
|
esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
|
Posted: Mon Apr 12, 2021 6:23 pm Post subject: Re: Broken IRS end gears. |
|
|
[email protected] wrote: |
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
What would be a good way to confirm it, then confirm you got rid of it? Gopro on the starting line? |
There are all sorts of systems to record suspension data (travel, velocity, cycles, etc). I helped a buddy set up the system on his motocross bike, and then he used the info to help fine tune the rates and valving. Super cool system, it linked via bluetooth to his iPad and gave you plenty of ways to look at the data. No doubt pricey but it would show you exactly whats happening. _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
|
Back to top |
|
|
[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
|
Posted: Mon Apr 12, 2021 6:27 pm Post subject: Re: Broken IRS end gears. |
|
|
esde wrote: |
[email protected] wrote: |
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
What would be a good way to confirm it, then confirm you got rid of it? Gopro on the starting line? |
There are all sorts of systems to record suspension data (travel, velocity, cycles, etc). I helped a buddy set up the system on his motocross bike, and then he used the info to help fine tune the rates and valving. Super cool system, it linked via bluetooth to his iPad and gave you plenty of ways to look at the data. No doubt pricey but it would show you exactly whats happening. |
Do you have any brand names, or links? |
|
Back to top |
|
|
esde Samba Member
Joined: October 20, 2007 Posts: 5966 Location: central rust belt
|
Posted: Mon Apr 12, 2021 6:30 pm Post subject: Re: Broken IRS end gears. |
|
|
This might be the one we installed
https://motioninstruments.com/products/moto-kit _________________ modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that. |
|
Back to top |
|
|
Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1660 Location: Marshallville Ohio
|
Posted: Tue Apr 13, 2021 6:13 am Post subject: Re: Broken IRS end gears. |
|
|
mcmscott wrote: |
You have wheel hop, you may not feel it but you have it. Stock irs end gears will sustain 11.60's in a full weight sedan if set up up correct. |
NOt really a fair statement.
It's about 60' times. Not 1/4mi ET's.
I was breaking Stock IRS splines at 13.50's running 1.7sec 60' times. (yes, proper setup and no wheelhop).
Now if you got the power to run 10.90's and back down on the launch to a 2.0sec 60', then yes, you can run 11.60's with stock stuff.
However, that's not normal drag racing.
There is no question that at 160hp, the weak link is the output splines.
I have seen more broken ones than I care to. I bet you have too......
Scott, I'm really surprised that you don't have more to share here.
I know that you do this stuff way more than I do and have lots more insight. |
|
Back to top |
|
|
mcmscott Samba Member
Joined: March 12, 2010 Posts: 4856 Location: sanger ca
|
Posted: Tue Apr 13, 2021 8:18 am Post subject: Re: Broken IRS end gears. |
|
|
My buddie was running 11.60s in a full weight 69 sedan, mid 1.60s 60 ft time.
I was racing the march meets in my 67, very braced car, solid mounted, solid mid mount, braced truss, brace from horns to the body and a couple other things. That car shot out of the hole without a shudder. Came back to the pits and a buddie says "you got some serious wheel hop" I tell him no way possible, he had a camera on a tripod behind all us racing. He showed me the vid in slow motion and you could see the stinger coming away from the body and returning about 3 in! You could also see the tires wrinkle, unload and move foward and back at the same rythem as the engine was moving. All this without feeling not even a shudder, trust me, you have wheel hop. Yes I have seen more broken trans parts than most anyone on this site.
I've slowed down trying to answer questions I know as facts due to all the people here that obviously know way more than myself about transaxles and would rather try to tell me I'm wrong. _________________ There are no stupid questions, only stupid people,
68 Ghia
67 T-1
65 Notch
02 Mexican beetle
74 Thing
15 Long travel rail
07 Nomad
05 f-250 |
|
Back to top |
|
|
Ohio Tom Samba Member
Joined: February 09, 2006 Posts: 1660 Location: Marshallville Ohio
|
Posted: Tue Apr 13, 2021 8:34 am Post subject: Re: Broken IRS end gears. |
|
|
Hey, thanks for sharing..
I got you to come out of your shell... LOL.. |
|
Back to top |
|
|
vwinnovator Samba Member
Joined: July 11, 2005 Posts: 1555 Location: Still doing it in the back of your VW
|
Posted: Tue Apr 13, 2021 8:35 am Post subject: Re: Broken IRS end gears. |
|
|
I ran 12.20's with thing/bus CV's and never broke a side gear..
but I also ran 7" slicks @ 14psi...
try dropping the tire pressure |
|
Back to top |
|
|
|