12 Bolt Failure



Several months ago I did extensive research to find someone to build the differential for my 73.
Both Mike and Gary were highly recommended and I could not find any negative comments or threads regarding poor work, or customer service.
I do have somewhat of a budget to build my car so cost was part of my decision to ask Mike to build the differential.
Mike was a little cheaper but not by much for like for like work.
As I stated earlier, so far I am pleased with the service I have received and hope the differential gives me years of good service.
Greg
I hope your build goes well and you get a reliable diff.
I am not saying that Mike's work is always bad as many people on the forum are quite content with it.
I even stood up for Mike back when Stinger12 was bashing him like crazy over an engine build several years back.
I just think people need to due their due diligence when lining up someone to do work for them.
Saving a few bucks may not be the best if you have a lot of HP in your build.
And I think that when something goes wrong with a build that people bring it to the forum's attention.
Otherwise it is just caveat emptor.
I have no dog in this hunt.
Bman

73BLWN, is the Hammerhead available for factory rear suspension? I thought it was only available in combination with the Detroit Speed Decalink rear suspension?
I was surprised how minimally polished the case was compared to other posts. I'm guessing that this whole fiasco is do to a rushed assembly, and he panic assembled it so I didn't take it from him and send it to Gary. We have a manufacturing plant in Tx. I had a trip scheduled, and was going to take some extra time off and personally go get it and ship it to Gary.
73BLWN, is the Hammerhead available for factory rear suspension? I thought it was only available in combination with the Detroit Speed Decalink rear suspension? Yes, I believe Jegs, and
Summit Racing sell it along with HammerheadIRS. I called Detroit Speed to confirm it was a direct bolt in. It was, DecaLink is the full system.
https://www.google.com/search?q=detr...=1563546158456
http://hammerheadirs.com/hotrod/
The truth of what lead to an actual event lies somewhere in between the two sides.
It would be interesting to hear the other side to this story.
Seems to be some "guessing" and speculation as to why this differential took so long to complete, how it was assembled and why there was a failure.
The truth of what lead to an actual event lies somewhere in between the two sides.
It would be interesting to hear the other side to this story.
Seems to be some "guessing" and speculation as to why this differential took so long to complete, how it was assembled and why there was a failure.
I was hoping to hear the other side as well here.... but after looking into this, apparently the "other side" has been banned from the forum due to some "he said/she said" BS that was reported to IB, (not related to 73BLWN's post) but someone else who is posting in here on this thread.... So everyone will not hear the "other side's" story.
The "other side's" story mentioned that all of the parts came from Tom's, the bolts/washers/carrier etc, it was all from Tom's kit and Tom's "machining" on the carrier. There was definitely lock tite and the assembly was torqued to spec. I was assured this would have been repaired under warranty both on labor and parts from Toms and there was communication issues. That's all that I will say about this, I'm not getting any further involved. Sucks for both sides for sure. I feel bad that 73Blwn had to come out of his pocket with a bunch of money to get rolling again. But there is definitely 2 sides to the story.
Hopefully 73BLWN's new diff serves him well and he can move on from this debacle.



People calling someone a rat seems a little harsh.
No one is banned that I KNOW OF.
One guy is back after years away with an agreement with IB.
The other guy left of his own accord when offered the same agreement.
And I know of no one who mocks this forum that is involved in this story.
Maybe people need to get their facts straight?
And maybe someone who has connections with Mike can see what he says about this obvious failure......that would be the "other" side of this story.
The Best of Corvette for Corvette Enthusiasts
I like OldCarBums comment its a good attitude: "I'm glad that you posted the possible cause and that others have chimed in with similar experiences.
Hopefully the information you provided to those, like Gary and Mike, who do excellent custom machining and assembly of our differentials, will cause them to look at these areas more carefully during assembly."
I'm not trying to get everyone all worked up. I just needed to get this off my chest and let people know what happened to me. I felt great going into my build with Mike, but clearly things didn't work out that great for me.
Thanks again to everyone who wished me good luck with my new rear end. I'm very excited to get it broke in and start testing it. When I rebuilt my short block last fall I installed Straub custom camshaft that is supposed to put me at a solid 757hp on pump gas. It was driving just great, I was having the best summer ever with my car. I'm hoping to get back to enjoying driving my car soon.



I like OldCarBums comment its a good attitude: "I'm glad that you posted the possible cause and that others have chimed in with similar experiences.
Hopefully the information you provided to those, like Gary and Mike, who do excellent custom machining and assembly of our differentials, will cause them to look at these areas more carefully during assembly."
I'm not trying to get everyone all worked up. I just needed to get this off my chest and let people know what happened to me. I felt great going into my build with Mike, but clearly things didn't work out that great for me.
Thanks again to everyone who wished me good luck with my new rear end. I'm very excited to get it broke in and start testing it. When I rebuilt my short block last fall I installed Straub custom camshaft that is supposed to put me at a solid 757hp on pump gas. It was driving just great, I was having the best summer ever with my car. I'm hoping to get back to enjoying driving my car soon.
Wish you the best from here on out.





I don't understand the people who pile on with all the support for the perpetrator when someone posts their bad experience as if it somehow nullifies the OPs experience. It is one thing to share your personal story, but to make excuses for Mike or criticize the OP in this situation is ridiculous. So let me share mine without prejudice.
Last year when I was considering a built 12 bolt for my C2 project, I attempted several times to contact Mike with no response. That’s fine. I sent one email to Gary which resulted in a very pleasant email conversation over several months where I learned a ton. When I pulled what I thought was the original pumpkin from my ‘64, Gary was right there via email helping me identify it as a C3 posi unit and explaining in detail the differences and pro/cons of the various years.
I ended up going with a Ridetech Track 1 set up that uses a Ford 9” with Truetrac dif. and custom half shafts with 1350 series ujoints. Again, Gary weighed in and gave me great counsel. He made nothing from this exchange other than an admirer and supporter. I never did hear from Mike.
Best of luck OP!
Oh, here’s a pic:
All welded up and installed.
Then add is a dual 3” exhaust.
SInce I live within 2 hours of New Haven CT, I have dealt with Gary 1:1 live which is extremely fortunate for me
Last edited by jb78L-82; Jul 21, 2019 at 01:27 PM.


I know I could make a list of non-supporting vendors that frequent not just the CF but many other forums. They specialize in blocks, cams, heads and entire crate long blocks and have a lot of backing from members on the forum that have never met them or bought their products but are convinced by their "sweet talk". Yes they are seeking our business using the forum as free advertising. As they are very combative I find they are easy to identify since their claims are correct regardless if what you know is true. I know of at least 6 I would like to list now but out of respect for 73BLWN and his thread I won't.
My advice is you don't need some small time non-supporting vendor to get the best product or price.
I know I could make a list of non-supporting vendors that frequent not just the CF but many other forums. They specialize in blocks, cams, heads and entire crate long blocks and have a lot of backing from members on the forum that have never met them or bought their products but are convinced by their "sweet talk". Yes they are seeking our business using the forum as free advertising. As they are very combative I find they are easy to identify since their claims are correct regardless if what you know is true. I know of at least 6 I would like to list now but out of respect for 73BLWN and his thread I won't.
My advice is you don't need some small time non-supporting vendor to get the best product or price.
Well if I could do it without getting banned here for life, I would tell you a story about the 6500 dollars I spent on a differential and 1480 axle kit I bought from a big supporting vendor here that was so poorly done, that it ate itself in 1800 miles. How about a rear spindle nut hand tight. Absolutely ridiculous. So I don’t know what whether or not a vendor is big or small, or supporting or not has to do with this. Bottom line is I had to spend another big number to have mine redone, so, yes, I got screwed by a very well respected vendor here. Obviously they shall remain nameless.
I am the guy Bman is referring to, although his portrayal of my situation is not totally accurate. Through many recommendations from many of the high horsepower guys here on the forum, I chose Mike to do my differential, trailing arms, steering box, and front spindles. It did take quite awhile, but a good part of it is we ran into a few big obstacles. For instance, nobody knew that the Ridetech trailing arms would not work with Tom’s 1480 axles because no one had tried it. So Mike had to do quite a bit of work to make them work. Then we had to wait for some parts as very little from my 1800 mile differential was reusable. I also decided I wanted REM and Cryo treatment on my parts. I feel, for the money I paid, I got great service from Mike. It was a very extensive build. It did take longer than I thought, but I feel I got a great product. I visited Mike and participated in the build. I have no doubt Gary is a great vendor as well. I have also met him and seen his shop.
I feel really bad for the OP. I am very surprised and will not attempt to make any excuses for anyone. As someone who had to pay twice for this work, I can feel your pain. I was going to stay out of this one until I saw the above post by Cardo. Just because they are big and supporting, doesn’t mean you won’t get screwed too. All one can do is try to get feedback and make a decision. Feedback on Mike was impeccable. Glad you were able to get back up and running.
Bill
I was surprised how minimally polished the case was compared to other posts. I'm guessing that this whole fiasco is do to a rushed assembly, and he panic assembled it so I didn't take it from him and send it to Gary. We have a manufacturing plant in Tx. I had a trip scheduled, and was going to take some extra time off and personally go get it and ship it to Gary.
73BLWN, is the Hammerhead available for factory rear suspension? I thought it was only available in combination with the Detroit Speed Decalink rear suspension? Yes, I believe Jegs, and
Summit Racing sell it along with HammerheadIRS. I called Detroit Speed to confirm it was a direct bolt in. It was, DecaLink is the full system.
https://www.google.com/search?q=detr...=1563546158456
http://hammerheadirs.com/hotrod/
By the way, when Mike did mine, his opinion is that due to where the posi cases always crack, that is the area he polishes. He doesn’t want to remove metal from areas that never fail. Your looks just like mine. Makes sense to me but nothing wrong if others have different ideas.
Bill
I am the guy Bman is referring to, although his portrayal of my situation is not totally accurate. Through many recommendations from many of the high horsepower guys here on the forum, I chose Mike to do my differential, trailing arms, steering box, and front spindles. It did take quite awhile, but a good part of it is we ran into a few big obstacles. For instance, nobody knew that the Ridetech trailing arms would not work with Tom’s 1480 axles because no one had tried it. So Mike had to do quite a bit of work to make them work. Then we had to wait for some parts as very little from my 1800 mile differential was reusable. I also decided I wanted REM and Cryo treatment on my parts. I feel, for the money I paid, I got great service from Mike. It was a very extensive build. It did take longer than I thought, but I feel I got a great product. I visited Mike and participated in the build. I have no doubt Gary is a great vendor as well. I have also met him and seen his shop.
I feel really bad for the OP. I am very surprised and will not attempt to make any excuses for anyone. As someone who had to pay twice for this work, I can feel your pain. I was going to stay out of this one until I saw the above post by Cardo. Just because they are big and supporting, doesn’t mean you won’t get screwed too. All one can do is try to get feedback and make a decision. Feedback on Mike was impeccable. Glad you were able to get back up and running.
Bill
Mike is in the process of assembling the super HD 10 for my 73.
To date he has been very informative and helpful to me as I know nothing about rear differentials.
Before I contacted Mike to build my rear end, I contacted several big name parts vendors like Tom's who highly recommended Mike Dyer to build my rear end and provided me with his contact information.
I posted a thread on this forum and another Corvette specific forum and, using no names, I received nothing but praise about Mike and Gary's ability to build quality units.
I chose Mike, mainly because the people who praised his work seemed to be those who actually raced or abused their equipment and stood behind Mike's product.
I did receive an almost equal praise for Gary's work however, the comments were mostly from those Corvette owners who drove their cars for mostly show, daily drivers and those who feel they get a better product just because it comes with a higher price.
Once I receive my rear end from Mike I will post a detailed thread regarding the work done, the parts used and my level of satisfaction of the unit itself, the quality of workmanship and after it's installed, how it stands up under the torque and horsepower of my build.
Last edited by OldCarBum; Jul 22, 2019 at 11:28 AM.


I can feel your pain. I was going to stay out of this one until I saw the above post by Cardo. Just because they are big and supporting, doesn’t mean you won’t get screwed too. All one can do is try to get feedback and make a decision. Feedback on Mike was impeccable. Glad you were able to get back up and running.
Bill
Well this isn't my battle to fight and many have experiences to share that say the non-paying vendors are just as reliable as any. So while it was a good deal for Bill and important he post his experience I think anyone can see how 73BWLN was not given just a defective part but totally abandoned and excommunicated. Would any normal vendor do that? I would think a valid business would have a difficult time avoiding an explanation. While someone within driving range of any vendor I expect would havel more influence than a distant customer.
Well this a forum and it gives everyone a chance to sort things out for themselves before spending their hard earned money. My sympathies go to 73BLWN here and wish I could say something that would help more than it will hurt.
For what its worth price had absolutely nothing to do with my decision. I had changed jobs, and cashed out nearly 300 hours of unused vacation pay. I had money to burn on an item I was dreaming about for years. I had a TKO 600 Extreme 5spd, I was so excited to complete my bullet proof drivetrain.
Yes, I'm very much an enthusiast. I've had my 73 since 1988. Replaced the frame, stripped and painted it myself, gutted it to a shell, and replaced or rebuilt nearly the whole car. It's right up there with my wife, family, and my dog. We don't have kids, but have helped raise our nieces, and grand nieces, including helping to pay for their private schooling. We're the cool aunt and uncle!















