1G AWD front roll stop - urethane vs. stock

[99gst_racer]

I just noticed that the urethane mount locates the hole in the center, whereas the stock one is a bit lower of center.

If this how it's supposed to be? If so, I wonder the reasoning behind the change of hole location?

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Stock on top of the urethane:

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I thought I remember seeing a thread about this a week ago, but I can't find it now...

 

[Arthris]

I noticed that when i put mine in. It was a pain to get the bolt to go through. Did it on the ground.

 

[ColtiXim]

This is why i have prefered keep my stock motor mounts and used this thing : Motor Mount Inserts - Liquid Urethane

I have used 80A shore, happy for the look result but still not tested.
Let me know if you want pics.

Remy

 

[99gst_racer]

I'm not looking to modify anything here, but thanks anyway. I'm just curious why the urethane mounted doesn't exactly match the stock one.

Can anyone verify that the hole of the stock mount is ndeed supposed to be off center?

 

[phantom_19]

Heat plus the engine putting weight on it transforms it a little. It probably sagged after all those years. Mine is doing exactly the same.

 

[RipperXX]

^ Along the same thing I was thinking. The only way to know for sure though would be to get a hold of a brand new OEM unit. (Which I would think, or rather hope is what was used for that pattern for the urethane one)

 

[99gst_racer]

I'm pretty sure the original mount has an off-center hole on purpose. It appears to be intentional, not worn that way.

 

[lowell]

If you look at a Prothane insert, it's offset down like stock. That manufacturer is probably just being lazy.

 

[Spyder FX]

That looks like you have the rear prothane installed in the front. I still use the 2 piece insert for this reason alone.

 

[99gst_racer]

If you look at a Prothane insert, it's offset down like stock. That manufacturer is probably just being lazy.

The Prothane in my picture is definitely centered. Not only does it look like it is, but it also measure out to be perfectly centered.

That looks like you have the rear prothane installed in the front. I still use the 2 piece insert for this reason alone.

The one in the pic is definitely the front prothane mount.

 

[Seamus]

Yes the factory 1g mount is off center. That mount is not "sagging".

The aftermarket OE replacment mounts such as an anchor are not offcenter either for some reason.

You'll find this differennce on the big upper mount by the timing cover too if you look at non OEM replacments.

 

[99gst_racer]

Here's another thing that's strange.

The front roll stop for a m/t car is a MB436490 and the front roll stop for an a/t is a MB581635.

The one in post #1 is marked with part number MB303505. Anybody have any insight on that?

 

[Seamus]

probably just succeded by those numbers you posted.

 

[99gst_racer]

My local Mitsu dealership says it's a current and available part number and has not been supersceeded.

 

[rts91tsi]

Here's another thing that's strange.

The front roll stop for a m/t car is a MB436490 and the front roll stop for an a/t is a MB581635.

The one in post #1 is marked with part number MB303505. Anybody have any insight on that?

There is a difference between the FWD and AWD M/T cars according to this pic from the tech manual.

 

[19Eclipse90]

Here's another thing that's strange.

The front roll stop for a m/t car is a MB436490 and the front roll stop for an a/t is a MB581635.

The one in post #1 is marked with part number MB303505. Anybody have any insight on that?

MB303505 is listed as a part for the...

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Mighty Mits dump truck, and as a front differential mounting bracket, no less. Interesting part you have there, Paul!

There is a difference between the FWD and AWD M/T cars according to this pic from the tech manual.

The geometry of the brackets themselves are completely different on 1Gs between FWD and AWD. What was posted is much closer to an AWD mount than a FWD mount as the FWD has a flat mounting surface.

 

[99gst_racer]

Wow, interesting indeed. I pulled it off my buddy's '93 GSX too.

Anybody got a side profile shot of a 91-94 AWD m/t front roll stop?

All I have here is the urethane one and the dump truck one...

 

[rts91tsi]

MB303505 is listed as a part for the...Mighty Mits dump truck, and as a front differential mounting bracket, no less. Interesting part you have there, Paul!

The geometry of the brackets themselves are completely different on 1Gs between FWD and AWD. What was posted is much closer to an AWD mount than a FWD mount as the FWD has a flat mounting surface.

I didn't realize I could copy and paste the part number into CAPS/ASA. Here is a screenshot of the part number illistration based off the PNC. It looks nothing like the mount pictured by Paul, but who knows how acurate the CAPS/ASA illistrations are to begin with.

I should have been a little more clear in my origional statement, for which I was thinking along the lines of the manufacturer pressed the wrong bushing into the mount because the brackets look the same.

My first DSM was a FWD/TSI, so I'm aware of the differences between the actual mounting bracket between them for the AWD/FWD models.

Sorry Paul, all I have is a side profile shots of an empty 93 AWD/MT mount, and one of a Prothane filled one, but none of the OEM Bushing.

 

[serviceguy]

I did a little research myself a few days ago, you can look it up here on a different board 1g engine mount

 

[99gst_racer]

I found this image in a Google search. This is an A/T mount vs. a M/T mount.

It seems the A/T mount has a hole that is more centered. This may be why Prothane chose to center the hole being that they sell the same part number for automatics and manuals. Though, the A/T mount looks to be larger in diameter, so I don't see how the urethane parts would interchange.

 

[rts91tsi]

Last I knew Prothane states the poly bushings to be for M/T only.

EXTREME PSI : Your #1 Source for In Stock Performance Parts

I asked on AT-DSM regarding poly bushings for the A/T mounts, and was told that the front one was the only one that was different in physical size.

 

[99gst_racer]

I can say that Prothane's catalog doesn't differentiate between transmission type. They list the same kit to fit FWD, AWD, and non-turbo. Typically when they don't mention transmission type, it's because they're the same anyway.

EDIT: Just got off the phone with one of Prothane's tech guys. He says the kit was developed for M/T cars only. He said the only difference is the front roll stop though, so the rest of the inserts would fit on an A/T car.

 

[rts91tsi]

You should have told Prothane how much their lack of a front roll stopper bushing for the A/T cars displeases the community.

I was researching a company who bulk sells polyurethane products/rods in hopes of perhaps finding a solution that fits correctly.

Polyurethane Rods | Precision Urethane

 

[ist dwa]

I found this image in a Google search. This is an A/T mount vs. a M/T mount.

It seems the A/T mount has a hole that is more centered. This may be why Prothane chose to center the hole being that they sell the same part number for automatics and manuals. Though, the A/T mount looks to be larger in diameter, so I don't see how the urethane parts would interchange.

Just as an FYI, the reason these are different is because the mount that bolts to the block itself are AT/MT specific. So sounds like if you want to do the whole mount poly u than you need an AT motor mount, or just do the inserts for MT cars.