4-pinion C7 diff write-up
10-20-2017, 04:48 PM
#1
Drifting
Thread Starter
4-pinion C7 diff write-up
Ok, so you’re worried about breaking the spiders in your c7, this is in my opinion a very reliable solution. I am still awaiting my CNC center block, and I need to machine the carrier and the larger cross pin. All I have for you right now is some teaser pics including ZR1 spiders and .746” cross pin. I will visit my machinist on Monday, and my block should be here by the end of the week.
Quite some time ago, I had a discussion with div7racr (Ed) about ford 9inchers with 4 pinions and he is the one who did the very first diff, a 2:73. He machined the first block and his is working just fine. Rflow (Albert) has done his and improved on the setup by drilling through the large pin AND a billet cnc block.
This mod has the right people and parts for total success
All I have right now is before pics, but I will update as I go along with more pics, and explaining the steps taken to machine the carrier and pin.
The Zr1 parts will set you back about 350.00, but the final pricing on the block is not set in stone. I would imagine demand would play a big role in it. I’ll have a better idea of the other machining costs next week.
I want to thank both Ed And Albert for the help and cooperation I have gotten from them both. I will be asking this diff to live through 1.28 60’s and I believe it will. Also worth mentioning is that this mod leaves the ELSD fully functional. Not an option with the wavetrac.
Anyhoo, hope you enjoy. Teaser pics:
Quite some time ago, I had a discussion with div7racr (Ed) about ford 9inchers with 4 pinions and he is the one who did the very first diff, a 2:73. He machined the first block and his is working just fine. Rflow (Albert) has done his and improved on the setup by drilling through the large pin AND a billet cnc block.
This mod has the right people and parts for total success
All I have right now is before pics, but I will update as I go along with more pics, and explaining the steps taken to machine the carrier and pin.
The Zr1 parts will set you back about 350.00, but the final pricing on the block is not set in stone. I would imagine demand would play a big role in it. I’ll have a better idea of the other machining costs next week.
I want to thank both Ed And Albert for the help and cooperation I have gotten from them both. I will be asking this diff to live through 1.28 60’s and I believe it will. Also worth mentioning is that this mod leaves the ELSD fully functional. Not an option with the wavetrac.
Anyhoo, hope you enjoy. Teaser pics:
04-01-2018, 06:38 PM
#6
Drifting
Thread Starter
Ok, the c6 spiders are very different from the c7 spiders in respect to the tooth profile. This makes for a minimal tooth contact as well as too much backlash if used in conjunction with c7 spiders. The ONLY way this provides any benefit is if all 4 c6 OR all 4 c7 (preferred) are used, no mixing. If mixed, the c6 spiders will have much more backlash and won’t bear any load at all until the c7 gears have broken. My diff will use 4 c7 gears, 2 of them have crower rod bushings installed to reduce the inside diameter to that of thec6 gears so I can use the c6 pin. The c7 pin and spider gears are unavailable right now. I am waiting on DSS shafts from Carlyle, when they get here, I will rob the spiders out of the 2.41 in my car to finish up the 2.73 I have modded and ready to assemble. Pics with bushings...
04-05-2018, 07:40 PM
#7
Drifting
Thread Starter
Now we are getting somewhere
More c7 spiders, now we just need our stub shafts to arrive from RPM.
Ant is drooling I’m sure, as I’ve already sent pics to him
More c7 spiders, now we just need our stub shafts to arrive from RPM.
Ant is drooling I’m sure, as I’ve already sent pics to him
04-05-2018, 09:21 PM
#9
Drifting
Thread Starter
I had that transmission bench custom made with drainage and mounts, and it’s made me more money than I can remember
Climate controlled and 2400 sq foot, trust me, I’m not suffering
Climate controlled and 2400 sq foot, trust me, I’m not suffering
Last edited by JHEBERT; 04-05-2018 at 09:21 PM.
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edster75 (11-26-2021)
04-05-2018, 10:25 PM
#10
Team Owner
Member Since: Jan 2007
Location: cookeville tennessee
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ttt
Looking good man looks like you have this down to a science on the work. Robert
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JHEBERT (04-06-2018)
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JHEBERT (04-06-2018)
04-06-2018, 02:58 PM
#14
Drifting
Thread Starter
^^^ Your billet block based on Ed’s drawings he sent us are the main component that makes this possible
John
John
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rflow306 (04-06-2018)
04-06-2018, 06:37 PM
#16
Drifting
Thread Starter
Ant, since you have the parts, your carrier should be machined for the larger cross pin, and the block the larger dia for all 4 holes. Bam! No rod bushings needed.
On another note, the rod bushings could be used in the carrier to facilitate using c6 gears and cross pin in the primary hole, eliminating the need to bore the holes in 2 of the c6 gears.
Depending on what parts you have access to, this can be done a couple of ways. I believe than my unit with the 2 rod bushings will be the best version yet, but we have the ability to do ANT’s using no bushings and only drilling the carrier and pin. At the time I machined my carrier, only the c6 pin was available to me.
On another note, the rod bushings could be used in the carrier to facilitate using c6 gears and cross pin in the primary hole, eliminating the need to bore the holes in 2 of the c6 gears.
Depending on what parts you have access to, this can be done a couple of ways. I believe than my unit with the 2 rod bushings will be the best version yet, but we have the ability to do ANT’s using no bushings and only drilling the carrier and pin. At the time I machined my carrier, only the c6 pin was available to me.
Last edited by JHEBERT; 04-06-2018 at 06:38 PM.
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rflow306 (04-06-2018)
04-06-2018, 06:55 PM
#17
Drifting
Thread Starter
DSS just arrived :)
Ohh yeah 
Last edited by JHEBERT; 04-06-2018 at 07:01 PM.
04-06-2018, 07:05 PM
#18
Ant, since you have the parts, your carrier should be machined for the larger cross pin, and the block the larger dia for all 4 holes. Bam! No rod bushings needed.
On another note, the rod bushings could be used in the carrier to facilitate using c6 gears and cross pin in the primary hole, eliminating the need to bore the holes in 2 of the c6 gears.
Depending on what parts you have access to, this can be done a couple of ways. I believe than my unit with the 2 rod bushings will be the best version yet, but we have the ability to do ANT’s using no bushings and only drilling the carrier and pin. At the time I machined my carrier, only the c6 pin was available to me.
On another note, the rod bushings could be used in the carrier to facilitate using c6 gears and cross pin in the primary hole, eliminating the need to bore the holes in 2 of the c6 gears.
Depending on what parts you have access to, this can be done a couple of ways. I believe than my unit with the 2 rod bushings will be the best version yet, but we have the ability to do ANT’s using no bushings and only drilling the carrier and pin. At the time I machined my carrier, only the c6 pin was available to me.
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JHEBERT (03-12-2019)
04-06-2018, 07:08 PM
#19
Drifting
Thread Starter
04-06-2018, 07:13 PM
#20