Driff

[St Louis SHO]

I'd post a pic but I'm on my droid.

 

[quake]

Dam, give me break on the spelling .

 

[Vnuk1]

Damn, give me a break on the spelling .

Fixed..

 

[WSC-SHO]

As far as I know I'm the only one who does the ring style welded diff. Not to knock tysho or area91 as they do fine work. Mine is provably 3x. The cost.

So HOW'D you say you did that again? Maybe post some pics? CAD, CAM drawings? Detailed blueprints maybe?...

 

[St Louis SHO]

My welded diff

How not to weld a diff

 

[Chuckblvd]

How not to weld a diff

WTF Now I have seen some s*** but damn!

 

[Vnuk1]

I believe that is the one that came out of the Turbo car...

 

[quake]

What a poor job!

 

[TYSHO]

My welded diff

First off, the work looks great!

The only problem I see with this design, is that the roll pin remains the only aid being used to keep the shaft from twisting, exactly like the stock differential. The twisting is what breaks the roll pins, ejecting the shafts. Once the roll pin breaks, this will create little bits of metal grinding inside the differential, which will then help speed up the process. This design only keeps the parts inside, while not helping retain the shafts from the twisting force they receive.

The style that AREA91 and myself use, help add strength to prevent the shaft from twisting loose. The bracket is welded to the shafts and rivets, which increases the holding strength. Instead of only having to break the roll pins, they have to break those and now the welds. They have to pass these two strength tests before the shafts can start spinning inside, eating away at the differential internals.


Anyway, I don't think any design is the ultimate cure. It's only a cure to help save the transmission casing from damage until you can afford a WaveTech or Quaife.

Here's a photo of a differential I serviced:

How not to weld a diff

And this is why I offer the free service, just incase the guy is lurking around.

 

[TYSHO]

No offense, but I'd want to see what you were going to do before sending my diff off to be welded.

This is how things go, really. Guy gets an idea, proves that it works well, offers the service, people copy it (or modify the idea to work better).

That's how it's suppose to go but there's guys who do what James posted not to do, screwing forum members.

 

[Bob Gervais]

That's how it's suppose to go but there's guys who do what James posted not to do, screwing forum members.

Gotcha. I thought you meant copying your exact design. And I agree, that other diff is atrocious!

 

[St Louis SHO]

First off, the work looks great!

The only problem I see with this design, is that the roll pin remains the only aid being used to keep the shaft from twisting, exactly like the stock differential. The twisting is what breaks the roll pins, ejecting the shafts. Once the roll pin breaks, this will create little bits of metal grinding inside the differential, which will then help speed up the process. This design only keeps the parts inside, while not helping retain the shafts from the twisting force they receive.

The style that AREA91 and myself use, help add strength to prevent the shaft from twisting loose. The bracket is welded to the shafts and rivets, which increases the holding strength. Instead of only having to break the roll pins, they have to break those and now the welds. They have to pass these two strength tests before the shafts can start spinning inside, eating away at the differential internals.

Weird. Of all the diffs i pulled apart, the pins were bent like a half moon from the pin trying to come out, not twist.

 

[AREA 91]

Weird. Of all the diffs i pulled apart, the pins were bent like a half moon from the pin trying to come out, not twist.

Far out. All the diff's I have taken apart we're the exact opposite.
One never really know's what to expect with a SHO.

 

[St Louis SHO]

Good info reguardless

 

[TYSHO]

Weird. Of all the diffs i pulled apart, the pins were bent like a half moon from the pin trying to come out, not twist.

I've had two differentials that the roll pins came out as you described, which is a very small percentage of the overall roll pins I have removed. This wear is caused by high speeds and quick deceleration, as the roll pin is trying to keep the pinion shaft from ejecting. Either way, bracket welding helps further protect against both of the problems that stress the stock design to failure.


The pinion shafts also have play in them with stock roll pins installed, which help destroy the stock design at a faster rate compared to pinion shafts that are held without any amount of play. By having the pinion shafts welded, all play is eliminated and the holding strength to keep the pinion shafts from ejecting is increased.

And, suppose the welds at the pinion shaft break from extreme twisting force [because the welds will not fail from the "moon shaped" problem], they will be contained within the differential [as your ring style brace does] by the bracket that is welded to the rivet. However, if you produce the extreme twisting force to break the weld, you have a serious problem inside the differential, meaning it's time to replace it with another one.

This is all where the life of the bracket welding differential comes into play, versus your ring style that uses the stock design to contain the pinion shaft. The failure rate with your ring style design is still at the stock rate, as the ring is only there to keep the shaft from ejecting when the roll pin has failed.


Please do not take this as a knock at your design, I'm just trying to help spread the information to provide better service in the future and inform others on the topic. I actually applaud you for coming out and sharing your design, there are others who refuse to come out to keep conversations like this from occuring and potentially losing service. I am still impressed with the great looking work performed with your design, it looks very professional. I am also confident you can come up with something to better your service, and wish you well in doing so.


I'm sorry for adding late to this thread and the ****** structure, I've been away for quite a few days and been up all night.

 

[hawkeye18]

Wouldn't it theoretically be possible to weld the ring to the pins as well? Now granted, I don't know much about welding, or how possible it is to weld aluminum to steel (I would imagine not that easy). I'm just wondering out loud here - I have zero experience with MTX diffs.

I remember somebody doing the ring-style mod with a much thinner steel hoop that was bent into shape and welded to the pins. I can't remember who did that, though.

 

[Bob Gervais]

Wouldn't it theoretically be possible to weld the ring to the pins as well? Now granted, I don't know much about welding, or how possible it is to weld aluminum to steel (I would imagine not that easy). I'm just wondering out loud here - I have zero experience with MTX diffs.

I remember somebody doing the ring-style mod with a much thinner steel hoop that was bent into shape and welded to the pins. I can't remember who did that, though.

The ring would have to be steel, as you mentioned. I'm envisioning either a steel ring with through holes at the pin locations, filled with weld. But then, you couldn't weld the ring to the diff housing.

With the aluminum ring, you can't weld the pins to the ring.

 

[quikSHOilver]

I remember somebody doing the ring-style mod with a much thinner steel hoop that was bent into shape and welded to the pins. I can't remember who did that, though.

Yes, Indeed I remember that too...couldn't remember who it was also. The ring thickness was about 12-16ga if that was what it seems?

 

[frosho]

I remember somebody doing the ring-style mod with a much thinner steel hoop that was bent into shape and welded to the pins. I can't remember who did that, though.

I believe that was SHO_DOODmorrris. He was working on some cool stuff (a SHO-powered AE86 Corolla), but I haven't seen any posts from him in months.

EDIT: Here is his welded diff thread - Check out my new welded diff and more ideas

 

[hawkeye18]

The ring would have to be steel, as you mentioned. I'm envisioning either a steel ring with through holes at the pin locations, filled with weld. But then, you couldn't weld the ring to the diff housing.

With the aluminum ring, you can't weld the pins to the ring.

Now correct me if I'm wrong, but wouldn't pinning the pins in place both laterally and rotationally be more important than having the ring be braced against the housing? The housing isn't what needs bracing - I don't see why it's a problem that the steel ring isn't welded to the housing.