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Tranny brace and Pfadt diff mount clearancing

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Old Oct 5, 2014 | 06:05 PM
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Default Tranny brace and Pfadt diff mount clearancing

In the course of reinstalling my drivetrain, I added an ECS tranny/diff brace along with replacing my stock diff mount with a used Pfadt mount I bought and had powder coated.

When I installed the assembly, I discovered that the lower passenger strut rod was uncomfortably close to the cross member.





Here's what the driver's side looks like - no issues.


The drivetrain will twist and flex as power is transmitted so no way was I going to leave it that tight. I broke out the air grinder and cut away a small piece to create the proper clearance and radiused the frame at the cut.


Much better. There is a substantial flange on the other side of the cut so no worries about weakening it.


After installing the Pfadt diff mount, I noticed a significant space between the pads and cross member that the shims that came with it would not fill so I cut a couple of pieces of self-adhesive high-durometer urethane I had and stuck them to the cross member under each pad - worked perfectly.


I also had to open up the vibration damper mounting holes a little and use a piece of urethane to ensure no vibration would be transmitted from the damper to the mount.


Anyone else have to make these kinds of adjustments to either of these products? No big deal as it's normal in the course of doing mods to make stuff fit properly - just curious.
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Old Oct 5, 2014 | 07:09 PM
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Really good job and the install look excellent.

Can you still get that trans mount?

I also have the ECS Brace and didnt have any fitment issues.

Although, I had to do some transmission case clearancing to allow my 3" stainless works exhaust to go over the axle without contacting the top edge of the trans. Like you, it was only minor material removal on the corner of a flange and didnt effect strength or operation.

BC
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Old Oct 5, 2014 | 07:19 PM
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Bill, I found the Pfadt mount used here in the 4-sale section and powder coated it black. Hoosier is now making a direct copy of this mount but they are charging a lot for it. Here's the one I bought:



I have seen a couple more come up for sale since so you can still find one for a good price if you keep your eyes peeled for it.
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Old Oct 30, 2014 | 08:15 PM
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Originally Posted by Patches
Bill, I found the Pfadt mount used here in the 4-sale section and powder coated it black. Hoosier is now making a direct copy of this mount but they are charging a lot for it. Here's the one I bought:



I have seen a couple more come up for sale since so you can still find one for a good price if you keep your eyes peeled for it.

Ive been looking to install this mount but since they are no longer available I was going to go with the Hoosier mount...you said they are asking alot for it? The current price listed is $364 and Pfadts site shows theirs was $449 so Hoosier is actually cheaper but i haven't been able to get any real comparisons on both mounts I might just have to bite the bullet and buy the Hoosier and hope its comparable
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Old Oct 30, 2014 | 09:25 PM
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Originally Posted by SpeedFreak87
Ive been looking to install this mount but since they are no longer available I was going to go with the Hoosier mount...you said they are asking alot for it? The current price listed is $364 and Pfadts site shows theirs was $449 so Hoosier is actually cheaper but i haven't been able to get any real comparisons on both mounts I might just have to bite the bullet and buy the Hoosier and hope its comparable
I noticed they dropped the price $25. I reverse-engineered the Pfadt mount and it was simple to measure and model in CAD so I can't imagine they went through all that trouble and got it wrong. I got mine used for a lot less than their price so I'd rather find a used one since it's cheap to replace the center bushing if needed and I doubt the pads are going to wear out any time soon. Plus, I think they're pretty easy to find as well.

Btw, I've seen two Pfadt braces come up for sale here in the past couple of months so they are still out there.
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Old Oct 30, 2014 | 10:41 PM
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I'll have to keep my eyes open for one and see how much it is, but you think they're pretty much the same quality then?
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Old Oct 30, 2014 | 11:18 PM
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Our diff mount clears the same as the Pfadt mount. We have no clearance issues. We have plenty in stock.

Thanks for your input and good luck on your search.
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Old Nov 3, 2014 | 03:12 PM
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Interesting. So the balancer on the diff was contacting the top of the Pfadt mount?
I've never heard that about the mounts.
As far as the brace goes, it's those fancy pancy swedged strut rods that gave you your clearance issue! lol
I have the DTE brace going in with my Pfadt mount. The wimpy steel struts should have no problems.
BTW, Thanks again for the bushing Patches. Having a backup is always a good thing ; )

And as far as you and removing your drivetrain.... now that you have done it more times than I can count...., what is the best method?
Should I unbolt the trans from the TT and drip the rear cradle first. Then pull the TT out on its own?
My clutch job is coming up. Just looking for advice.
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Old Nov 4, 2014 | 12:03 AM
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I'd never heard anyone complain about the damper touching the mount either but that may be a source of some of the vibration complaints.

As far as the brace strut clearance, I think the shorter Hinson motor mounts may be contributing to that a bit and also the normal tolerance variations of the castings, etc.

I always drop the rear cradle with the brakes and suspension attached and then pull the tt/tranny/diff as a unit but it can be easier to pull them separately if you don't have a lift.
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Old Nov 4, 2014 | 12:10 PM
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Originally Posted by Patches
I'd never heard anyone complain about the damper touching the mount either but that may be a source of some of the vibration complaints.

As far as the brace strut clearance, I think the shorter Hinson motor mounts may be contributing to that a bit and also the normal tolerance variations of the castings, etc.

I always drop the rear cradle with the brakes and suspension attached and then pull the tt/tranny/diff as a unit but it can be easier to pull them separately if you don't have a lift.

In my installation directions, it was clearly stated that you remove the dampener when using the Pfadt mount. I didn't have any clearence problems, and I have the ECS brace, also. You really keep a clean car, Patches.
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Old Nov 4, 2014 | 12:39 PM
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What's the difference between the DTE and the ECS braces?
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Old Nov 4, 2014 | 01:39 PM
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Originally Posted by SpeedFreak87
What's the difference between the DTE and the ECS braces?
Aluminum strut rods(as pictured) are used in the ECS kit. The DTE kit uses steel rods. I have the DTE kit but think the ECS kit has a nicer look to it. I'm sure it's only cosmetic though. Either will do its job.
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Old Nov 4, 2014 | 01:40 PM
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Originally Posted by zeevette
In my installation directions, it was clearly stated that you remove the dampener when using the Pfadt mount. I didn't have any clearence problems, and I have the ECS brace, also. You really keep a clean car, Patches.
Do you still have the instructions?
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Old Nov 4, 2014 | 02:27 PM
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Originally Posted by zeevette
In my installation directions, it was clearly stated that you remove the dampener when using the Pfadt mount. I didn't have any clearence problems, and I have the ECS brace, also. You really keep a clean car, Patches.
Cool - I will pull it off. I didn't have the installation instructions since I bought mine used and couldn't find installation instructions ( PM'ed a few folks, but, no cigar). I lft the dampener on wondering if the harmonics were even affected by the Pfadt mount and figured better safe than sorry.

FYI, I found you need to be careful posting manufacturer installation instructions here as they are generally copyrighted and the mods will delete any posts with them attached or pictured.

Thanks for the info.

I bought one of each of the tranny braces - the DTE is all steel while the ECS is all aluminum. They are both essentially the same and probably perform similarly but I liked the lighter aluminum and the look of the ECS brace so installed that and sold the DTE.
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Old Nov 4, 2014 | 02:55 PM
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Hmmm, always thought the ECS brace was steel with aluminum rods. Didn't realize it's all aluminum. Sweet.
Also, the instructions are still on Pfadt's site. I just read it over.
http://www.pfadtracing.com/c5_corvet...tallation.html
And in case nobody has heard, sounds like they are back or will be shortly. They just posted yesterday on facebook that they will be at SEMA and that they are on the comeback. Good news.
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Old Nov 4, 2014 | 04:19 PM
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Imagine that - on their website.

Thanks for the info. And, yes, I heard they are back.
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Old Nov 5, 2014 | 09:58 AM
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My entire drivetrain was literally sitting on one of those brace bars with the cradle under it and nothing happened. Think it'll be okay.
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Old Nov 5, 2014 | 11:00 AM
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Couple things - 1) I'm OCD, so what I had was unacceptable to me and, 2) I'm trying to head off any sources of NVH where ever possible. Might as well now while I'm working on it.
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Old Nov 5, 2014 | 11:58 AM
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I think Pfadt made a mistake by mounting their diff brace metal to metal. I was uncomfortable doing this, so I just improvised. I think the diff brace has some effect on handling, too. I'm not a racer, but there's a different feel to the car, powering out of turns, that is more stable. I vaguely remember adjusting, or reversing one of the rods on my trans brace to create more clearance. I looked and found my original instructions, but they're identical to the link posted.
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Old Nov 5, 2014 | 12:26 PM
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Would you happen to have any extra shims? I think I might need two.
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