DIY - How To: Transmission Mount Change SC300/SC400 5spd or Auto
08-20-07, 07:15 PM
#17
hey guys i just finished installing my tranny mount. i must say.... it feels realy damn good! This is a must for all SC with vibrations!!! very easy to do.. only took me 20-30 mins. only problem now is i think i need to replace my engine mount. THANKS CLUBLEXUS for the DIY!!!!!!!!!
11-21-07, 04:37 PM
#23
I installed my new mount 4 days ago... and besides it just being great to have a new part in there (and that the old one was nearly in two pieces when I removed it) it's done NOTHING at all for my vibration. Next I'll replace the Engine Mounts. Then if that's not it, I'll check the center drive shaft bearing. If that's not it I'll look at the U-Joint more closely (although that looks prim and proper to the eye). If THATs not it..... man I don't know?!~ Unbalanced tire? Watch it be that too....... lol - my luck.
Anyway, yeah - new tranny mount here as well and that's all good - but it's not the fix for everyone's 70mph vibration.
Anyway, yeah - new tranny mount here as well and that's all good - but it's not the fix for everyone's 70mph vibration.
12-04-07, 11:20 AM
#24
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CLRH2O
Just cause your U-joint looks "prim and proper" doesn't necessarily mean it's not bad. Depending on how long your transmission mount was bad (seeings how you said it was practically in two pieces I would say it's been bad for awhile), could have caused the u-joints to wear prematurely.
With U-joints, changing the operating angle of the joint (which can be caused by the transmission, engine mounts or center shaft bearing being bad) causes a cyclic change in the rotational speed of the driven shaft. The greater the operating angle, the greater the speed changes in the shaft. The speed of the driveshaft also amplifies U-joint-induced vibration. The maximum acceptable operating angle of a U-joint decreases in direct proportion to shaft speed. At 2,000 rpm, the maximum angle is about 8°, while at 4,000 rpm, it is only about 4°.
If it were me I would start with swapping out the u-joints and the center shaft bearing. Hell, make a day of it and do the engine mounts while you're under there. Then if you still have your vibration, take it and trade it in on a new Lexus and don't worry about it.
Just cause your U-joint looks "prim and proper" doesn't necessarily mean it's not bad. Depending on how long your transmission mount was bad (seeings how you said it was practically in two pieces I would say it's been bad for awhile), could have caused the u-joints to wear prematurely.
With U-joints, changing the operating angle of the joint (which can be caused by the transmission, engine mounts or center shaft bearing being bad) causes a cyclic change in the rotational speed of the driven shaft. The greater the operating angle, the greater the speed changes in the shaft. The speed of the driveshaft also amplifies U-joint-induced vibration. The maximum acceptable operating angle of a U-joint decreases in direct proportion to shaft speed. At 2,000 rpm, the maximum angle is about 8°, while at 4,000 rpm, it is only about 4°.
If it were me I would start with swapping out the u-joints and the center shaft bearing. Hell, make a day of it and do the engine mounts while you're under there. Then if you still have your vibration, take it and trade it in on a new Lexus and don't worry about it.
12-04-07, 02:55 PM
#25
has anyone looked into getting a polyurethane trans mount and possibly motor mounts? i love them on my buddies 240. i think i will buy that windshield sealing compound that becomes very hard when cures and fill in the factory mount. this was it will be almost like a solid mount. and very cheap too. great DIY. i knew how to do since i did my clutch already but its just so much better with pics.
12-07-07, 05:37 AM
#26
Driver School Candidate
If you haven't checked your tire's balance yet and are looking at all of these other possibilities, then you should just take it to a mechanic to ask them to fix it. 
Here's a tip.
Check the wheel balancing. It just might save you a ton of money.
Here's a tip.
Check the wheel balancing. It just might save you a ton of money.
05-06-08, 10:23 PM
#27
Thread resurrection!
I've recently changed the transmission mount on my 1995 SC300 5speed. I must say it feels much better! It was very straight forward and just as stated, I was able to complete the task within 20 minutes. Here are some pics of the mounts that I got from Toyota dealer.
Part number is 12371-46090. Cross reference to N/A Supra 5speed mount.
Paint was flaking a little before installation.. I supposed that's normal!?
Side by side comparison. Note the difference.
After all was said and done, I noticed that shifter is now sitting a about 1/2 inch taller.. Granted, new mount is much more rigid and is obvious that it would cause the shifter position to be higher.. I guess I need to find me a different shift ****.
I've recently changed the transmission mount on my 1995 SC300 5speed. I must say it feels much better! It was very straight forward and just as stated, I was able to complete the task within 20 minutes. Here are some pics of the mounts that I got from Toyota dealer.
Part number is 12371-46090. Cross reference to N/A Supra 5speed mount.
Paint was flaking a little before installation.. I supposed that's normal!?
Side by side comparison. Note the difference.
After all was said and done, I noticed that shifter is now sitting a about 1/2 inch taller.. Granted, new mount is much more rigid and is obvious that it would cause the shifter position to be higher.. I guess I need to find me a different shift ****.
12-15-08, 08:59 AM
#28
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I did this on my Automatic 99 sc300
i use to get vibration when i cross about 4500 rpm wot ... coins in cup holder use to rattle ....
Now its like i'm crusing at 2000 rpm at WOT
reving happily and smooth!]
also.. the old mount looked good when mounted on .. but when i took it out one of the bushings was split in two... no wonder.... so looks may be deceiving
If u haven't done this yet .. ur in for a surprise.... best 50 bux spend
i use to get vibration when i cross about 4500 rpm wot ... coins in cup holder use to rattle ....
Now its like i'm crusing at 2000 rpm at WOT
reving happily and smooth!]
also.. the old mount looked good when mounted on .. but when i took it out one of the bushings was split in two... no wonder.... so looks may be deceiving
If u haven't done this yet .. ur in for a surprise.... best 50 bux spend
Last edited by portion; 12-15-08 at 09:04 AM.
