Poly transmission mount = more power?

Two questions here, actually.

I just installed a Daystar poly transmission mount over the weekend because mine had been broken for years, and unforunately I should have done some research on this issue before purchasing it. Little did I know, these suckers are taller than the OEM style and now I'm hearing a loud rattle or grinding noise at random intervals with the engine running (whether in neutral or in gear.) I'm guessing this is due to the taller mount and I would need to drop the cross-member to correct this?

Either way, because I'm going to be installing a 5 inch lift next month I'm afraid I'm going to have to ditch the whole extra-tall poly mount idea and stick with the OEM rubber style. My only concern is: would I be losing any amount of power due to the flex of the rubber mount? Do the poly mounts offer less power-loss?

I had to drop my xmember more after I put the poly in too...I like the peace of mind having a tough mount in there, no more shearing mounts, i hope

you shouldnt notice a power difference with either material. with the poly, it may feel like you launch a little faster and have slightly better throttle response initially after you hit the go . you also might add some life to the engine mounts with the poly.

Just find out where it's rubbing and break out the BFH.

XJZ said:

Just find out where it's rubbing and break out the BFH.

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BFH? Umm, you're gonna have to enlighten me on this one...

Big F'n Hammer

A motor mount has no effect on the power output what so ever.

Evidently Daystar hasn't fixed their mount design. I installed one last year and the extra height caused serious vibes on deceleration (stock height XJ - d44 rear) . i contacted them and their tech said the mount would settle down after use - I removed it and instaled lfetime Autozone rubber mt.

Assessing the damage...

I took a look under the hood last night and it turns out the vibes I was getting was the fan cluth rubbing into the radiator. Needless to say, I was pretty pissed. I just replace the radiator about three months ago with a brand new CFS 3 core! It doesn't look like any of the cores were cut but just scraped up a bit so hopefully there will be no leaking. I put some JB Weld on the scraped areas just in case. Afterwards I removed the Daystar poly mount and replaced it with an Autozone Anchor mount. TONS less vibes, plus it has a lifetime warranty.

So what have I learned from all this? Poly transmission mounts from Daystar are lame.

-Venom

I replaced my trans and motor mounts a few weeks ago, and it does seem like there is more power. I know there isn't really more, but it is actually getting to the rear tires, instead of twisting the motor and trans around, albiet a little bit. You cannot see my motor move, at all. It used to torque to one side when you revved it. The energy that used to move my motor is now heading where I want it to. Same thing is happening on yours.

I compared a brand new tranny mount from DC to one from Kragen and AUtozone and it seems that the DC was slightly shorter and angled for better fit. If the poly one makes you need to drop the crossmember then it's definately the wrong one for the application.
Oh... and if you're breaking tranny mounts, did you also replace engine mounts? all three are ussualy done together.

I ate two radiators (from my stockpile of used parts) during my piecemeal battle with motor and trans mounts(learned a lesson there)...fixxed it with currie mounts and the daystar trans mount...if it comes loose again I'll just weld in solid mounts...it already feels solid :shiver: :shiver:

A life time warranty on a cheap mount is like a 100,000 warranty on a hyundai...hope it makes you feel all warm and fuzzy while your waiting for the tow truck

If you want plug and play poly or rubber fail proof mounts go to Mountain Off-Road Enterprises.

They don’t cause radiator damage. After sending my fan into a radiator because of a failed stock style mount, I went to M.O.R.E.'s Poly mount set up. Lots of transmitted vibes, but IMHO worth it for the strength.

When they were R&D'ing the new rubber style, I called and told them I wanted one of the first sets. Much better design now. Still more vibes than stock, but not as much as poly. This design is strong and will not fail.

Will AutoZone pay for a radiator when their lifetime mounts fail?

Pay for quality and only cry once.

Bones :skull1:

cherokee89 said:

I replaced my trans and motor mounts a few weeks ago, and it does seem like there is more power. I know there isn't really more, but it is actually getting to the rear tires, instead of twisting the motor and trans around, albiet a little bit. You cannot see my motor move, at all. It used to torque to one side when you revved it. The energy that used to move my motor is now heading where I want it to. Same thing is happening on yours.

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Your motor isn't twisting as much because the new mounts are transmitting the same torque more efficiently to the chassis. The net result is you reduce engine movement, but increase body movement. In both cases, the movement is a reaction to the power being applied at the ring gear. In the case of my 5 spd '90 in first gear/low range; a maximum of 225ft/lbs X 3.93 X 2.72 or 2,405ft/lbs of torque.

That's a pretty big job for those little rubber biscuits.