Stiffness in Shifting
Thread Starter
Instructor
Joined: Jun 2017
Posts: 213
Likes: 139
From: SF Bay Area
Stiffness in Shifting
Hey RL, I was in the mountains last weekend, had a hard emergency stop while in gear to dodge an animal. I didn’t kill the engine or stall, but at the time of braking I’m pretty sure my hand was braced on the gear shift and on the clutch seeking neutral as fast as possible.
When I got back on the road, I noticed that getting into and out of 2,4,6 (a pulling motion) is very stiff/sticky. Requires an unusual amount of force. 1,3,5 all shift beautifully.
I’ve been researching countless threads and am thinking of a few culprits of what may have happened here. The thread below seems like an extreme circumstance I’d like to avoid (dropping the gearbox and rehearing)
https://rennlist.com/forums/993-foru...-6-help-5.html
I did a transmission flush the next day and test drove it. Definitely a worthwhile job as it helped a bit and needed to be done.
I got under the car this evening and tried to isolate the stiffness by disconnecting the rear rod. I captured a video that shows difficulty with the shift rod connection point. Verified the gearbox seal looks good with the usual slight bit of oil weeping.
I also used the downtime as an excuse to deep clean the shuttle, shift tube, and lubricate the bushings. I noticed a lot old grit at the lower rubber boot from various disintegrated materials as things age out.
Shifting is also hard with the motor off (captured the same in the video).
Any tips here? Should I adjust the forward rod? This car has both the short shift kit and golden rod from Fister. They’ve been excellent but I’m curious if they need adjustment over time. I have some upcoming plans to do my motor mounts. They aren't sagging, but I want to replace them just to keep things tight and refreshed.
Rusty input shaft splines? (Hope not!)
When I got back on the road, I noticed that getting into and out of 2,4,6 (a pulling motion) is very stiff/sticky. Requires an unusual amount of force. 1,3,5 all shift beautifully.
I’ve been researching countless threads and am thinking of a few culprits of what may have happened here. The thread below seems like an extreme circumstance I’d like to avoid (dropping the gearbox and rehearing)
https://rennlist.com/forums/993-foru...-6-help-5.html
I did a transmission flush the next day and test drove it. Definitely a worthwhile job as it helped a bit and needed to be done.
I got under the car this evening and tried to isolate the stiffness by disconnecting the rear rod. I captured a video that shows difficulty with the shift rod connection point. Verified the gearbox seal looks good with the usual slight bit of oil weeping.
I also used the downtime as an excuse to deep clean the shuttle, shift tube, and lubricate the bushings. I noticed a lot old grit at the lower rubber boot from various disintegrated materials as things age out.
Shifting is also hard with the motor off (captured the same in the video).
Any tips here? Should I adjust the forward rod? This car has both the short shift kit and golden rod from Fister. They’ve been excellent but I’m curious if they need adjustment over time. I have some upcoming plans to do my motor mounts. They aren't sagging, but I want to replace them just to keep things tight and refreshed.
Rusty input shaft splines? (Hope not!)
Last edited by JSF; Aug 18, 2023 at 04:10 AM.
Instructor
Joined: Feb 2023
Posts: 169
Likes: 76
From: Nottinghamshire
The Goldenrod can cause gearbox damage with harsh or rapid changes. Understandable as all compliance between the gear lever and the box is non existent with the loss of the rubber 'donut'.
First thing to try, as it is only one the rearmost gear changes, is adjusting the forward rod because this controls gear lever travel/stop. The stress of your unintentional stop may have pushed something out of adjustment (e.g. engine moved foward on bushes). If you are in there you may as well replace all the silicone bushings (4), plastic bushes (4) and the two rod bushes.
First thing to try, as it is only one the rearmost gear changes, is adjusting the forward rod because this controls gear lever travel/stop. The stress of your unintentional stop may have pushed something out of adjustment (e.g. engine moved foward on bushes). If you are in there you may as well replace all the silicone bushings (4), plastic bushes (4) and the two rod bushes.
Last edited by Heuerman; Aug 19, 2023 at 07:37 AM.
Thread Starter
Instructor
Joined: Jun 2017
Posts: 213
Likes: 139
From: SF Bay Area
The Goldenrod can cause gearbox damage with harsh or rapid changes. Understandable as all compliance between the gear lever and the box is non existent with the loss of the rubber 'donut'.
First thing to try, as it is only one the rearmost gear changes, is adjusting the forward rod because this controls gear lever travel/stop. The stress of your unintentional stop may have pushed something out of adjustment (e.g. engine moved foward on bushes). If you are in there you may as well replace all the silicone bushings (4), plastic bushes (4) and the two rod bushes.
First thing to try, as it is only one the rearmost gear changes, is adjusting the forward rod because this controls gear lever travel/stop. The stress of your unintentional stop may have pushed something out of adjustment (e.g. engine moved foward on bushes). If you are in there you may as well replace all the silicone bushings (4), plastic bushes (4) and the two rod bushes.
Racer
Joined: Mar 2021
Posts: 286
Likes: 166
From: South FL
Great outcome to share. I spent the weekend doing a transmission flush, lubricating the shuttle and various bushings. The most important item was to adjust the forward rod a bit (shortened it a pinch) and we are back to the bolt-action shifting feel. All of the bushings were still in great condition as they were refreshed when Darin did the GR+SSK.
I had a similar problem, my transmission was pretty noisy and the shifts were everything other than smooth. I also just did a flush with fresh 75W-90SL and now the car drives like new. I would have never thought that filthy transmission lubricant could have such an impact on the quality of the shifts. Alas, learned something new.
Instructor
Joined: Feb 2023
Posts: 169
Likes: 76
From: Nottinghamshire
Great outcome to share. I spent the weekend doing a transmission flush, lubricating the shuttle and various bushings. The most important item was to adjust the forward rod a bit (shortened it a pinch) and we are back to the bolt-action shifting feel. All of the bushings were still in great condition as they were refreshed when Darin did the GR+SSK.
I meant to post the Porsche instructions for adjusting the front rod so for future reference of others, here they are:
Thread Starter
Instructor
Joined: Jun 2017
Posts: 213
Likes: 139
From: SF Bay Area
Havent seen this diagram before, but very helpful and thanks for sharing! Really happy with the forward rod sold by Darin. Having the Heim joints offer a lot more precision.
