6MT front diff backlash, preload, pattern - Page 2

Scargod · 01-02-2022, 11:57 AM

I would go with the 1.25, per the 6MT manual. My 2008 STI FSM agrees.
The "1.75" I've seen, but I believe that is for the 5MT.
The difference in the two preloads is .00183" IF the threads of the ring are 1.5mm. I did not easily have a transmission to measure the threads per mm when I wrote this.
I think that's a significant preload to get wrong.

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JarHarms · 01-03-2022, 09:37 AM

The most recent 2015my and 2007my FSMs I have for a 6MT (TY85 non-split case) also lists 1.25 tooth pre-load. That is the spec I would use in your case.

As for the 1.75 -vs- 1.25 earlier in this thread; I am not certain if this difference was due to earlier FSM spec being 1.75 or some other reason.

Shaneil · 01-04-2022, 05:41 AM

Cheers guys appreciate the input, yeah I just checked mine and it appears the the factory set mine at 1.75?

01-03-2022, 09:37 AM	#27
JarHarms Scooby Specialist Member#: 138994 Join Date: Jan 2007 Location: apparently I "spread the hate" Vehicle: 2006 WRX, 6MT, 5x114	The most recent 2015my and 2007my FSMs I have for a 6MT (TY85 non-split case) also lists 1.25 tooth pre-load. That is the spec I would use in your case. As for the 1.75 -vs- 1.25 earlier in this thread; I am not certain if this difference was due to earlier FSM spec being 1.75 or some other reason. Last edited by JarHarms; 01-04-2022 at 03:57 PM. Reason: (sp)

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01-02-2022, 11:57 AM	#26
Scargod Scooby Specialist Member#: 260314 Join Date: Oct 2010 Chapter/Region: NESIC Location: S central CT, New England Vehicle: 2007 STI silver gray metallic	I would go with the 1.25, per the 6MT manual. My 2008 STI FSM agrees. The "1.75" I've seen, but I believe that is for the 5MT. The difference in the two preloads is .00183" IF the threads of the ring are 1.5mm. I did not easily have a transmission to measure the threads per mm when I wrote this. I think that's a significant preload to get wrong. * Registered users of the site do not see these ads.

01-04-2022, 05:41 AM	#28
Shaneil Scooby Newbie Member#: 114292 Join Date: May 2006	Cheers guys appreciate the input, yeah I just checked mine and it appears the the factory set mine at 1.75?