 Ring and Pinion Backlash, What's everyone doing? |
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| Matt Romanowski |
 Apr 15 2013, 07:11 PM
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#1
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Senior Member  Group: Members Posts: 878 Joined: 4-January 04 From: Manchester, NH Member No.: 1,507  |
For the folks who are rebuilding their own transmissions, what are you using for a backlash measurement? The manual says around .007, but that seems a little tight. We're trying to get some temperature out of the transmission and were thinking about running a little looser. Anyone tried that?
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Replies
| Dr Evil |
Oct 9 2013, 12:10 PM
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#2
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Send me your transmission! Group: Members Posts: 23,041 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region 
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Going to more teeth on the pinion of a 901 will actually net you a weaker pinion as the teeth will be smaller/thinner. The 915 is thicker overall in all parts.
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| Jon B |
Oct 9 2013, 02:08 PM
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#3
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Member Group: Members Posts: 73 Joined: 28-September 13 From: Vista, CA Member No.: 16,448 Region Association: None |
QUOTE(Dr Evil @ Oct 9 2013, 11:10 AM)  Going to more teeth on the pinion of a 901 will actually net you a weaker pinion as the teeth will be smaller/thinner. The 915 is thicker overall in all parts. More teeth increase the gear's load bearing surface and help decrease material fatigue. Gear tooth design can be adjusted if the pinion isn't enlarged, for example, the root circle can be increased, shortening the tooth. It's unlikely that Porsche would've offered a weaker design with no specific advantage, such as significant change in ratio. The 915 8-tooth pinion was increased in size from previous 7-tooth pinion, with ring gear offset 2mm on differential. Jon B. |
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Posts in this topic
Matt Romanowski Ring and Pinion Backlash Apr 15 2013, 07:11 PM
Mark Henry I wouldn't try that, maybe it's time for a... Apr 15 2013, 08:34 PM
Matt Romanowski
I wouldn't try that, maybe it's time for ... Apr 16 2013, 05:15 AM Mark Henry I don't race so mine is just stock.
But, I... Apr 16 2013, 08:02 AM pcar916 :agree: The backlash and contact pattern go work... Apr 16 2013, 08:16 AM Matt Romanowski You can have good settings and contact and still b... Apr 16 2013, 08:29 AM Dr Evil I use the factory tool, or at least a clone of it.... Apr 16 2013, 11:58 AM Jon B The factory states that .012-.018 is tolerance... ... Oct 6 2013, 10:32 PM Jon B
I use the factory tool, or at least a clone of it... Oct 7 2013, 10:49 PM Dr Evil
[quote name='Dr Evil' post='1850919' date='Apr 16... Oct 8 2013, 10:34 AM 396
[quote name='Dr Evil' post='1850919' date='Apr 1... Oct 8 2013, 12:31 PM Dr Evil Not using inches, why would you assume so? Decimal... Oct 6 2013, 10:35 PM Jon B
Not using inches, why would you assume so?
I didn... Oct 6 2013, 10:57 PM 396
Not using inches, why would you assume so?
Hi, I... Oct 7 2013, 05:44 PM Dr Evil Sure, whatever Oct 7 2013, 12:26 AM Matt Romanowski Jon - Good call.
As an update, we're going to... Oct 7 2013, 06:19 AM 76-914
Jon - Good call.
As an update, we're going t... Oct 7 2013, 08:19 AM Jon B
As an update, we're going to pull the transmi... Oct 7 2013, 10:00 PM r_towle Matt, what kind of differential do you use?
Rich Oct 7 2013, 07:56 PM Matt Romanowski
Matt, what kind of differential do you use?
Rich... Oct 7 2013, 11:32 PM zambezi
[quote name='Jon B' post='1936884' date='Oct 6 20... Oct 7 2013, 08:18 PM Dr Evil Ya, in my free time ;) Sorry, I am at my 9a-9p job... Oct 8 2013, 12:41 PM Dr Evil Search on Pelican as the guy who made them had a t... Oct 8 2013, 12:41 PM jimkelly see post #43
http://www.914world.com/bbs2/index.p... Oct 8 2013, 12:47 PM Dr Evil Um, no. That is not it. Oct 8 2013, 12:49 PM Matt Romanowski Post 21 shows one though. Oct 8 2013, 01:25 PM sixnotfour http://forums.pelicanparts.com/porsche-911...tml#p... Oct 8 2013, 01:56 PM Dr Evil
http://forums.pelicanparts.com/porsche-911...tml#... Oct 8 2013, 02:42 PM r_towle Matt,
Have you considered replacing the diff hous... Oct 8 2013, 07:44 PM Matt Romanowski
Matt,
Have you considered replacing the diff hou... Oct 8 2013, 08:25 PM Jon B We have a billet intermediate plate and side plate... Oct 8 2013, 09:35 PM Matt Romanowski
We have a billet intermediate plate and side plat... Oct 8 2013, 10:46 PM Jon B Matt,
You realize that's alot of engine and t... Oct 8 2013, 11:32 PM Matt Romanowski
Matt,
You realize that's alot of engine and ... Oct 9 2013, 06:07 AM r_towle
Matt,
You realize that's alot of engine and ... Oct 9 2013, 11:19 AM Jon B Can you replace the ring and pinion with the 8 too... Oct 9 2013, 12:07 PM John I use the VW tools. Got them to do 915's, but... Oct 8 2013, 07:52 PM Jon B John,
Those are excellent tools, and Porsche-reco... Oct 8 2013, 09:18 PM John
John,
Those are excellent tools, and Porsche-rec... Oct 9 2013, 08:18 PM 914forme Okay the magic mystery tool is really not needed. ... Oct 9 2013, 07:17 AM pcar916
Now Pinion Backlash, I hate doing that, shims, pu... Oct 9 2013, 08:24 AM Dr Evil Agreed, I hate setting preload. <_< Oct 9 2013, 08:23 AM Dr Evil I disagree. When it comes to the 901 pinion, more ... Oct 9 2013, 02:19 PM Jon B More teeth increase the gear's load bearing su... Oct 9 2013, 03:01 PM Dr Evil
We can disagree.
In any case it's really no... Oct 9 2013, 03:08 PM Dr Evil Late, but none the less relevant. Oct 9 2013, 04:30 PM Jon B It only began in April, so not quite a resurrectio... Oct 9 2013, 05:13 PM Dr Evil Yup, relevant, addressed two misplaced decimals, I... Oct 9 2013, 05:31 PM Jon B John,
I have more than one bar, but keep the smal... Oct 9 2013, 10:00 PM Jon B 914 Transmission
Measuring differential bearing pr... Oct 11 2013, 03:46 PM 396 Thanks for the indepth education. Now we know who ... Oct 11 2013, 03:54 PM Jon B 914 Transmission
Setting Ring & Pinion
Factor... Oct 11 2013, 04:03 PM |
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