Author Topic: Anyone looking for a rearend with a taller ratio????  (Read 85284 times)

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Offline John Burk

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #45 on: January 19, 2014, 02:16:47 AM »
Joe Law at one point was turning his QC pinion 16,000 rpm and it worked alright as far as I know . Has anybody had rpm related pinion bearing problems .




Offline Dynoroom

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #46 on: January 19, 2014, 01:50:16 PM »
I looked into using a Strange Engineering drop out 12 bolt for the 2.29 gear set in a 9" Ford. The problem is it will only work with a series 1 or 2 gear set and the 2.29:1 is a series 3 and won't fit the case IIRC.

As a side note Glen Deeds & Bill Ward both ran 7.5" rear ends with Deeds roadster twin turbocharged making well over 1500 hp (record 282)
and Wards ran a blown big block in a Opel. So I'd say it's already been proven to work. History can be your friend....
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Offline desotoman

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #47 on: January 19, 2014, 01:55:44 PM »
Back in the 1980's, I talked to a team that was having pinion bearing problems with their Halibrand champ Q-Change when running 300 mph. Their problem got solved by changing ring and pinion in the Q-Change from 4.11 to 3.63. Also that was before synthetic oil was common.

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Offline Sumner

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #48 on: January 19, 2014, 03:29:23 PM »
I looked into using a Strange Engineering drop out 12 bolt for the 2.29 gear set in a 9" Ford. The problem is it will only work with a series 1 or 2 gear set and the 2.29:1 is a series 3 and won't fit the case IIRC.

As a side note Glen Deeds & Bill Ward both ran 7.5" rear ends with Deeds roadster twin turbocharged making well over 1500 hp (record 282)
and Wards ran a blown big block in a Opel. So I'd say it's already been proven to work. History can be your friend....

Thanks, that is good info.  Nice to have someone who knows the history  :cheers:,  so maybe we will reconsider the 7.5 for the Stude.  The only bad thing will be hearing Sparky telling me "I told you so"  :cry:

Sum

Offline Sumner

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #49 on: January 19, 2014, 03:34:57 PM »
Mike, forgot to ask ..... what were they running for a center section?  Spool, Posi, minispool, welded spiders?  Also do you know by any chance how many splines the axles were?

Thanks,

Sum

Offline desotoman

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #50 on: January 19, 2014, 05:22:17 PM »
Sum,

I am not familiar with the GM 7.5 inch rear end. What is the smallest diameter of the pinion shaft that could twist in two. That is an area where you might find the weak link.

Years ago when Flatfire was running, Speedway Engineering found a 3.5 or 3.6 ratio that would fit into the Q-change in the car. When the car started to approach the 300mph range they were starting to twist the pinion shaft. To my knowledge non ever broke, but I know they did replace one or two gear sets for those reasons.

Below is a Q-change  pinion shaft from the Modified Roadster that I own. The previous owner had a blown fuel motor in the car that made 3000 Hp and 3000 Ft lbs Torque. The ring and pinion were 1-1 with Q-change gears making the final drive as I recall 1.67-1 or there about. This part of the pinion would twist when the the tires would spin then bite at El Mirage. The torque spike at that instant was too great for the minor diameter of the Quick change pinion shaft.

This car was only run at El Mirage, except for going to Bonneville once, where it ran the fastest 2 1/4 mile speed ever run at the time, but a transmission bearing keep it from possibly setting a record. The only reason I am mentioning this is that depending on conditions the traction at El Mirage can be much better than Bonneville, so if you are building a high HP car with lots of torque to run both venues, you might want to take that into consideration.

Tom G.
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Offline John Burk

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #51 on: January 19, 2014, 06:55:47 PM »
Just measured a 2.14 pinion I have have . The input splines are 1.17" od  , Past the splines the smallest diameter  is 1.125" and the outer bearing journal is 1.187".

Offline Sumner

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #52 on: January 19, 2014, 07:01:54 PM »
..I am not familiar with the GM 7.5 inch rear end. What is the smallest diameter of the pinion shaft that could twist in two. That is an area where you might find the weak link...

You make a good point there.  The pinion shaft is ....



... as you can see, a bit smaller in dia. on the 7.5 than the larger 8.75 and I'm not real sure of the dia. of the axles at this point as I haven't pulled them, but with that in mind and what Mike said (and Sparky) the 7 1/2 might work for the Stude also. 

I will go with 28 spline aftermarket axles for my car and we would do the same with the Stude as the Torsen takes 28 splines.  Most 7.5's with the stock carrier are 26 spline.  There are also some full spools out there for them, but more expensive than the Ford stuff.  After what I saw Sparky do with his old car and the way it hooked up I think the Torsen is the way to go and you can find them for under $150 on ebay.  They, like most carriers come in two series and you need the 2 series for the tall gears.  They came in Camaro/Firebirds, late 90's early 2000's. 

The pinion shaft is 27 splines on the 7.5 and it took me a while to find a 1350 yoke for it but I did.  I bit the bullet and got the longer splined G-Force transmission yoke (1350 also) and it is rated for way more HP than I'll ever make but if I sell the transmission down the road someone else might benefit from it.  I'm having a 10 inch drive-shaft made up.  It should be done in a week or so when they get the yoke from G-Force,

Sum

Offline John Burk

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #53 on: January 19, 2014, 08:00:38 PM »

Offline kiwi belly tank

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #54 on: January 19, 2014, 09:02:59 PM »
The Sonoma with a 10 bolt has a flat four bolt pinion flange on the rear if anybody is interested.
Also I had Mike at B&J build me some Greek Couplers for my 7.5 10 bolt 4WD setup in the liner so he has them available now too.
  Sid.

Offline tauruck

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #55 on: January 20, 2014, 01:19:16 AM »
Bingo!

I found a company capable of manufacturing 9" gear sets.
The owner is not phased about quantity but I need to get the centre section to him.
He knew right away what I was talking about as he's done Ford 9" hypoid before for drag racing over here.

I was given all the technical jargon about why he needed the centre section intact.

I'll give you all an update on the progress.

One photo of his work.
« Last Edit: January 20, 2014, 01:25:24 AM by tauruck »

Offline Dr Goggles

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #56 on: January 20, 2014, 04:36:35 AM »
Hey Sum(yeah and the rest of ya) our 7.5 install is a kind of(I think) unique one in that we essentially transplanted the GM pumpkin with a Torsen centre between the Ford axle tubes , we used Ford 28 spline axles AND I used the Ford yoke that came off the 8.8(or whatever it is, we call it a "Borg Warner")...the only thing I had to do was make a spacer because the collar on the pinion spline is shorter on the Ford yoke and wouldn't put the preload on the bearing.....

Some think like that anyway......
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Offline 38flattie

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #57 on: January 20, 2014, 12:49:10 PM »
Sum, I left a 7.5" out of a Camero at Randy Jackson's(wrenchbender).

Hooley could call Randy and grab it, if he wants.
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Offline Sumner

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #58 on: January 20, 2014, 01:08:14 PM »
Hey Sum(yeah and the rest of ya) our 7.5 install is a kind of(I think) unique one in that we essentially transplanted the GM pumpkin with a Torsen centre between the Ford axle tubes , we used Ford 28 spline axles AND I used the Ford yoke that came off the 8.8(or whatever it is, we call it a "Borg Warner")...the only thing I had to do was make a spacer because the collar on the pinion spline is shorter on the Ford yoke and wouldn't put the preload on the bearing.....

Some think like that anyway......

Yes we also need to change to the Ford ends for the rules.  Which axle tubes did you use?  The 7 1/2 I have has 2 5/8 inch tubes and the Ford ones that I've seen are 3 inch.   The Fords have 3/16 inch (sorry for the non-metric talk) thick tubes so 2 times 3/16 is 3/8 the difference between the O.D. of the 7.5 and the I.D. of the Ford tubes.  To me that looks like I could cut the GM tubes a ways outside the pumpkin and slide Ford tubes on them cut to the right length and weld them to the pumpkin and also plug weld them to the GM stubs inside of them?

Does the Ford 8 inch have smaller tubes?  I'd like to mill the plug welds out of the stock tubes and pull them out and just put new tubes in.  I could weld Ford outer bearing ends on the axle tubes I have but I think the track width might then be too narrow as the 7 1/2 I have has a narrow tread width.  I'll know more if that will work soon.

Interesting about the yoke but I was able to find the 1350 yoke on sale for $94 and it is a direct fit.  Thanks for the info about the Ford 28 spline axles working as I have the same center section.

Sum, I left a 7.5" out of a Camero at Randy Jackson's(wrenchbender).

Hooley could call Randy and grab it, if he wants.

Thanks, and I'm sure we want it (Hooley doesn't know yet but I'll call him).  Either he or John will go and get it and thanks,

Sum

Offline Dr Goggles

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Re: Anyone looking for a rearend with a taller ratio????
« Reply #59 on: January 20, 2014, 03:41:37 PM »
Sorry Sum I don't spend much time on a full size computer and I've jjust spent half an hour trying to find the relevant bits on my fartsmone.......go to page 165 of Australian Bellytank,halfway down the page are some pics.....I got some hollow bar turned down and we just used some massive all-thread to pull it into the axle tubes from the pumpkin. That suited us because our rear end is narrowly supported and doing that pur a lot more metal in there.

Trust me those plug welds are harder than goatskneesium, it's due to the weld alloying with some nickel or something, don't point any expensive tools at them,blow them out,ask Sparky, he'll confirm that.
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

http://thespiritofsunshine.blogspot.com/

Current Australian E/GL record holder at 215.041mph

THE LUCKIEST MAN IN SLOW BUSINESS.