What if I didn't use shim?


Michael Flare

My Final Heaven
Joined
Mar 11, 2010
Messages
418
Hi. I was wondering if you guys can tell me what would happen if I didn't shim the area between the differential bearing and the transmission case. Last year, I installed an MFactory LSD into my transmission and I did not use a shim because I had no idea how they work and where to put it. Can you guys explain the negative effects of it? Right now it seems like my Input Shaft Bearing is ruined and it's only been a year old! My car for the past year would make a bad noise but it would go away when I press down on the clutch pedal so it's the ISB for sure that got ruined. I also couldn't go in gear until the car was fully warmed up the past few months. It's gotten so bad now that my car can't go into any gears at all! Could not using the shim be the problem?
 


b16 mini

Ek9 obsession
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If you don't understand shims then I doubt you have shimmed the input shaft correctly to suit the new bearing,

If you didn't use any shims then your diff will likely be moving from side to side as you accelerate due to the helical cut of the gears pushing each other apart.

If you didn't use the correct input shaft shim then the same thing could be happening there or alternatively it could be to tight putting excessive pressure on the bearings.

I would suggest getting some one with experience to inspect your gearbox to decide if it is worth salvaging
 


Michael Flare

My Final Heaven
Joined
Mar 11, 2010
Messages
418
If you don't understand shims then I doubt you have shimmed the input shaft correctly to suit the new bearing,

If you didn't use any shims then your diff will likely be moving from side to side as you accelerate due to the helical cut of the gears pushing each other apart.

If you didn't use the correct input shaft shim then the same thing could be happening there or alternatively it could be to tight putting excessive pressure on the bearings.

I would suggest getting some one with experience to inspect your gearbox to decide if it is worth salvaging
The tutorial I was following only shows the adding of a shim between the differential bearing and the transmission case. The input shaft has two big washer looking things that literally sits right above the input shaft bearing (one ring is flat and one ring is concave and they're stacked on each other from the factory and the tutorial says to put it back like that during reassemble); I don't know if these washer looking things are also known as shims that you mentioned but the tutorial says to reuse those because nothing really changes on the input shaft but the differential does change because it's an LSD installation guide. I bought new differential bearings, new throw out bearing, new input shaft bearing. I'm gonna open up my transmission and measure the clearance where I'm supposed to put a shim with a feeler gauge and buy the appropriate sized shim. I hope the problem will be solved after this.
 


Leej8

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Joined
Oct 12, 2015
Messages
1,618
The tutorial I was following only shows the adding of a shim between the differential bearing and the transmission case. The input shaft has two big washer looking things that literally sits right above the input shaft bearing (one ring is flat and one ring is concave and they're stacked on each other from the factory and the tutorial says to put it back like that during reassemble); I don't know if these washer looking things are also known as shims that you mentioned but the tutorial says to reuse those because nothing really changes on the input shaft but the differential does change because it's an LSD installation guide. I bought new differential bearings, new throw out bearing, new input shaft bearing. I'm gonna open up my transmission and measure the clearance where I'm supposed to put a shim with a feeler gauge and buy the appropriate sized shim. I hope the problem will be solved after this.
Can you update this Michael as to the problem and how you fixed it ? Or did you find a solution?
Sorry for bumping up old posts but a update to your problem would help others out
Thanks
 


Michael Flare

My Final Heaven
Joined
Mar 11, 2010
Messages
418
Can you update this Michael as to the problem and how you fixed it ? Or did you find a solution?
Sorry for bumping up old posts but a update to your problem would help others out
Thanks
This was on my old engine. What happened was that there's a very strong grinding noise when I'm off my clutch pedal so it's most likely Input Shaft Bearing which is the problem. The first time I installed the MFactory LSD (replaced major bearings with new ones) , I didn't shim it. I drove it for several months and that's when the sound came on. I took the transmission apart and replaced the major bearings again but this time I correctly shimmed the new LSD to the transmission. However, only after one month, the same noise came back. I'm assuming it's none of these problems. I think I had a cheap clutch and flywheel setup. I have a completely new engine now with expensive clutch parts. The old engine had the ultra light Fidanza 7.5 lbs flywheel with a Yonaka Stage 3 6-puck clutch and pressure plate. I have a feeling this is a cheap combo even though they're both popular brands. The setup I have on my engine now is Competition Clutch 8.5 lbs flywheel with Competition Clutch Stage 4 6-puck clutch and pressure plate combo. It is absolutely perfect with no problems with the transmission left untouched and stock on the new engine. In the future, I'm going to dissect the old engine and try to replace some stuff and see what the problem is because the MFactory LSD was $800!
 


Leej8

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Joined
Oct 12, 2015
Messages
1,618
Thanks Michael for the update, it would be interesting to see what the problem was , and hopefully you can put it to rest when you open up the old box .
All the best Michael .
 


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