Play at the gearstick - How much is too much?

[Vanya]

Hello all!

 

So I've gone and torn out my entire gearshift assembly after having refurbished the translator end last fall and being disappointed due to remaining play/slop in the longitudinal direction at the gearstick.

 

I put it down to worn bushings, and figured a refurbed master unit might be the key to having a tight and somewhat accurate gear selection. 

 

Having torn out the master unit however, my isolatorbushings seem to be in fantastic condition with one of them having lateral movement of maybe 1 mm (which would consequently only introduce play in the lateral direction - not my case). While my plastic spherical bearing bushes appear to be a little loose, I fail to see how any of this would eliminate lost motion/free play in the longitudinal direction when selecting gears.

 

A friend of mine has probably the best kept '89 Turbo SE in Sweden (if not the world) and I recall checking his gearshift and discovering it had no play whatsoever. Am I remembering wrong?

 

Those who have SE's - how much play is "normal" - is it possible to get a "modern" feeling gearstick without any slop in any direction. 1 cm would maybe be tolerable but I think I have closer to 6-7 cm.

 

According to LEW, who had their gearshift check out by Lotus themselves, the following points were made:

 

• Free play in the neutral position (mainly felt side to side) (NOT VALID IN THIS CASE)
In a new unit the play in the bushes result in approx. 1mm of movement on the mechanism which is felt as about 4mm at the Gearknob (Ratio is 4:1)

 

• Free play when selecting gear (mainly felt as lost motion before gear is selected) (MY CURRENT PROBLEM)
In a new unit this lost motion is as a result of three things :-

a) Clearance in the selector mechanism in the gearbox (Haven't checked)
b) Movement in rubber isolator bushes at cable connection (at Master Unit). These isolators are to reduce noise being transmitted from the gearbox to the gearlever. - (Not by the looks of it)
c) Clearance in the cables. Cables have an ‘S’ bend in the early vehicles (L/H shift) which contributes to free play. (New cables would probably reduce play) - (Mine's a 91MY so isn't really an early car is it? Furthermore, my cables have no free motion in them whatsoever)

 

Anyways I'd really like to hear everyone's input - those of you who have pristine/show cars - what kind of play do you get? Where do I give up/set my expectations?

 

I'll rebuild my unit this weekend and get back with some info. I'd also like to put together a guide to complement Paul93Lotus's fantastic thread on refurbing the master unit, perhaps posting it to LEW as well.

 

Thanks a million in advance,

 

Regards,

Vanya S.

[sanj]

Yours is still an early car, as surely the cables are attached on the left side of the transaxle. The right hand shift wasn't introduced until '93.5.

 

Does your car have a steady bracket with ball bearing on the shift arm coming out of the transaxle?

[Vanya]

Hi Sanj,

 

When you say steady bracket, are you referring to the cross shaft support bearing as per the image below (in which case my car doesn't have one!)

 

http://www.lotusespritworld.com/images/Technical/Gearbox/Gearbox_Translator.jpg

 

Does the cross shaft bend due to loading? I think I've heard something along those lines before...

 

Which cars had the support bearing anyway? Could my friend's stock 89' SE have it?

[sailorbob]

Are you positive the movement is not in the master and/or cables? This is easily checked with the aid of a friend by disconnecting the cables from the translator and seeing if they move when the gear lever is moved.

 

If the translator tie rod is badly worn or if its ovaled its mounting holes in the translator or exhaust sub frame then this causes excessive movement before a gear can be selected.

Edited June 29, 2013 by sailorbob

[Vanya]

I've got everything off the car at present. The translator was refurbished last autumn, and outfitted with new rose joints and bearings - it's very tight and no play whatsoever. The cables themselves have no lost motion - when I push or pull one end of the cable, I get an immediate response at the other end of the cable. So the cables seem healthy. I'm gonna hang them up and let some gearbox oil trickle down through the sleeve so they get a little extra lubrication though.

 

I'm gonna replace the bushings on the master unit even though everything seems to be in good shape (except maybe the spherical bearing bushes which have a little play).

 

When the cables were in place though they were held in place in the grooves both at the master unit and in the rear (where they were also pressed down with the metal bracket). The two cables and red hose were cable tied in 4 places along the mounting so I guess cable motion is ruled out.

 

How much free motion do you get at the stick (forwards backwards) ?

[sailorbob]

I have very little free play but the S4 has the shorter shift translator and master unit and that may behave slightly differently.

 

Is your translator tie rod and its mounting holes in good condition? When I first bought my car I had to get the mounting hole in the translator arm welded up and re-drilled because the tie rod had been allowed to chew the bore up.

[Vanya]

Ok status update:

 

I reassembled the car today and discovered a number of things (some of which make me want to kick myself):

 

1. A lot of play in the longitudinal plane was coming from a loose translator - the pinch-bolt holding it together wasn't tightened properly. I need to start taking thread locking compounds more seriously. Anyway the thing that shocked me was that, as loose as it was, the woodruff key should block that motion - I guess it needs to be remachined to better match the groove in the translator itself. Until that happens, I suppose a thread-locked bolt is the best solution.

 

2. Another source of play (lateral play this time) is in the nylock nuts at the base of the translator - inability to tighten these sufficiently against the base of the translator body (due to the rose joints spinning at the base) allows for minimal free play which is detrimental to both feel and gearchange ability. I'm gonna mount standard nuts with locking compound. This should be fine as the rose joints themselves allow for rotational motion.

 

3. At the master unit there's free play due to the spherical bearing bushes not being a perfect fit for the grooves in the housing - this allows the levers holding the cables to move maybe 1-2 mm which translates into a lot more free play at the gearstick.

 

4. Both cable levers at the master unit can move a few mm laterally at the cables - no amount of tightening resolved this for me and the crinkle washers don't seem to be pressed against the rest of the mechanism. I don't know if everyone elses unit is like this, but I couldn't see a way of tightening the unit together any more than I have.

 

Anyway I now seem to have a lot less play - maybe 1-2 cm forwards/backwards and 1 cm side to side. Still seems more than Factory spec but I don't see how I could make it any better. With regards to forwards backwards play, that seems to come entirely from the box itself - there's a "dead zone" between gear selections. Not much to do about it I suppose.

[sanj]

Hi Sanj,

 

When you say steady bracket, are you referring to the cross shaft support bearing as per the image below (in which case my car doesn't have one!)

 

http://www.lotusespritworld.com/images/Technical/Gearbox/Gearbox_Translator.jpg

 

Does the cross shaft bend due to loading? I think I've heard something along those lines before...

 

Which cars had the support bearing anyway? Could my friend's stock 89' SE have it?

That is what I was referring to. Your car probably has the strengthened shaft extension, which did away with the need for the support. Your friend's '89 almost certainly has the older setup, my '90 did.

[mdw]

Sjs do the modified shaft for £78 plus the vat and postage.  

[jonwat]

 

2. Another source of play (lateral play this time) is in the nylock nuts at the base of the translator - inability to tighten these sufficiently against the base of the translator body (due to the rose joints spinning at the base) allows for minimal free play which is detrimental to both feel and gearchange ability. I'm gonna mount standard nuts with locking compound. This should be fine as the rose joints themselves allow for rotational motion.

You can cut a slot into the end of the threaded section with two blades in a hacksaw which would enable you to stop it from spinning while you tighten it with a ratchet ring spanner. 

[Vanya]

John - good idea, but I'm slightly worried it'd ruin the thread of the rose joint doing that. I'm gonna adjust the translator end carefully using regular nuts. Once I find it within spec I'll put some thread locker in there and...well, if the nuts yield, they yield - if they don't, I guess I'll just have to Dremel a little and get new rose joints. But that should hopefully lie a few years down the road. Most important thing right now is getting a modern feeling gearshift!