Author Topic: Question about improved gearshift linkage  (Read 3486 times)

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Offline invjbo

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Question about improved gearshift linkage
« on: Monday,August 17, 2015, 06:21:57 AM »
I was wondering if anyone know if the procedure described in the bulletin Improved Gearshift Linkage also applies to the 5-speed gearbox to ease up on the spring tension when moving in to reverse. The idea is that the spring is shortened and thus releaseing the tension.

http://www.lotus-europa.com/manuals/bulletins/improved_gearshift_71_24.pdf

Best regards
John
Lotus Europa S2 -71
VW Golf Gti -16
Bayliner 2455 -01
BMW S1000XR -16
Husqvarna Fe 450 -16

Offline Grumblebuns

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Re: Question about improved gearshift linkage
« Reply #1 on: Monday,August 17, 2015, 06:52:39 AM »
The service bulletin pictures the 336 gearbox and is dated 1971, so I would say that is only for the 336 and not for the 365.

Offline Jesspo

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Re: Question about improved gearshift linkage
« Reply #2 on: Monday,August 17, 2015, 07:46:27 AM »
Hi John,

i modified a bit the middle Point of the linkage which gives a great improvment in shifting. My car was easy and fine to shift when cold but after a Minute drive it was more and more stiff to shift.
Sorry my english is limited so it is hard to explain. In the turn point which is fixed on the gearbox is a rubber ush with a liner from top and one from buttom. When you tigthen the screw in this rubberbush the rubberbush is fixed and the outside metal tube turns in the rubber. I made a new liner between the both liners so that the rubber bush can turn free in the liners. Now it is much easier to shift.

greetings Frank

Offline Grumblebuns

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Re: Question about improved gearshift linkage
« Reply #3 on: Monday,August 17, 2015, 09:39:12 AM »
Forgot to mention that Peter Boedker offers an alternate kit that replaces the detent at the rear of the 365. I ordered one but have not yet installed it to comment on it's effectiveness.

Joji Tokumoto
Fallbrook, Ca

Offline invjbo

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Re: Question about improved gearshift linkage
« Reply #4 on: Monday,August 17, 2015, 11:21:09 PM »
Hi John,

i modified a bit the middle Point of the linkage which gives a great improvment in shifting. My car was easy and fine to shift when cold but after a Minute drive it was more and more stiff to shift.
Sorry my english is limited so it is hard to explain. In the turn point which is fixed on the gearbox is a rubber ush with a liner from top and one from buttom. When you tigthen the screw in this rubberbush the rubberbush is fixed and the outside metal tube turns in the rubber. I made a new liner between the both liners so that the rubber bush can turn free in the liners. Now it is much easier to shift.

greetings Frank

Frank, thank you for your reply. I donĀ“t really understand how you did your alterations. Perhaps you have some photos to add to the discussion?

Best regards
John
Lotus Europa S2 -71
VW Golf Gti -16
Bayliner 2455 -01
BMW S1000XR -16
Husqvarna Fe 450 -16

Offline 3929R

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Re: Question about improved gearshift linkage
« Reply #5 on: Tuesday,August 18, 2015, 08:24:26 AM »
Attached is the parts diagram, which may help the conversation. Frank, did you make a part that fits between parts #14? In the original design did tightening the nut/bolt draw the two #14 pieces together thereby compressing the #13 rubber bushing, causing it to expand and lock against the sleeve of part #12? Did a metal spacer between parts #14 would allow tightening of the nut/bolt without squeezing the #13 rubber bushing?

As an alternate approach, I replaced my worn rubber bushing with polyurethane. More info here-  http://www.lotuseuropa.org/LotusForum/index.php?topic=62.0 Also, follow that link for info on how I got fifth gear to work.

To achieve shifting nirvana I believe you need to address the bushings (#3) at the bottom of the shift lever(#2), the center link/middle pivot (#11, 12, 13, & 14), the rear linkage attachment at the gearbox (right/back end of #10), AND have the length of the linkage properly adjusted (adjustment done where #9 threads to 8 & 10). If any of the plastic or rubber bushings are sloppy, the shifting will be sloppy. If the linkage attachment at the gearbox is loose, you will have shifting problems. If any part of the center pivot is loose, you will have shifting problems. If everything is tight but out of adjustment at the center pivot or the gearbox, you will have shifting problems. But when all is right, it does work.

I haven't quite reached nirvana but can find all 5 gears and reverse all the time without feeling like I'm stirring pudding. Everything works! My only annoyance is a rattling noise from the bottom of the shift lever. I am using oilite bushings (with an original type shoulder bolt from RD) and wonder if the original design plastic bushing would cure the rattling noise, but at the cost of decreased durability. I have plastic bushings from RD but the rattle is not enough motivation to reach back into the tunnel to install them!

Mark
Salt Lake City, Utah, USA

Offline Jesspo

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Re: Question about improved gearshift linkage
« Reply #6 on: Tuesday,August 18, 2015, 11:50:55 AM »
Hi

yes the Picture helps to explain. I made a liner netween both liners 14, this selfmade part is 0,1mm longer the the rubberbush 13 inside have. So the rubberbush can turn easy in the liners 14 and the selfmade distance liner.

I think without this selfmade distance, you tigthen the nut and bolt and the rubberbush 13 is fixed. Now the turnpoint is around the rubberbush and part 12 must turn in the rubber. Because all this parts are very near to the exhaust, you can shift fine in the first Minute when it is cold, but with temperature on the exhaust the shiffting is like Pudding.

In the rubberbush 13 is a metal tube so you can not tighten this an compress it.

greetings Frank

Offline 3929R

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Re: Question about improved gearshift linkage
« Reply #7 on: Tuesday,August 18, 2015, 01:17:45 PM »
Frank, As I understand your set up, I wonder if the bushing sleeve (#12) will slide over (up or down) the bushings (#13 & 14) and rub or bind on the bracket (#11)? Peter Boedker reported this problem and recommended that I periodically check to see that mine is staying in place. If it moves, he recommended installing a set screw in the
Mark
Salt Lake City, Utah, USA

Offline Jesspo

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Re: Question about improved gearshift linkage
« Reply #8 on: Tuesday,August 18, 2015, 01:58:25 PM »
Hi Mark

You are right. I made a washer on the downside of part 12 so it has no chance to lve down

I try to made a picture in the next days. The Europa is an other garage in the moment

Offline invjbo

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Re: Question about improved gearshift linkage
« Reply #9 on: Wednesday,August 19, 2015, 12:20:36 AM »
Hi,

I suppose the explanations given refers to a TC shift linkage. I have a S2 where the Engine and gearbox are changed to a Crossflow and 5-speed gearbox but the gear linkage is more or less the same.

Best regards
John
Lotus Europa S2 -71
VW Golf Gti -16
Bayliner 2455 -01
BMW S1000XR -16
Husqvarna Fe 450 -16

Offline 3929R

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Re: Question about improved gearshift linkage
« Reply #10 on: Wednesday,August 19, 2015, 08:54:59 AM »
Ops. Yes I assumed if you had a 5 spd, you had a TCS.
Mark
Salt Lake City, Utah, USA