free hit
counters
5th gear gone - Gearchange/Gearbox/Clutch - The Lotus Forums Jump to content
Sign in to follow this  
CharlieC

5th gear gone

Recommended Posts

Yesterday took a short and gentle drive onto the autobahn (thanks to the rear view mirror coming steadily away from its mount) I got onto another autobahn section and opened up in 4th. Nice and steadily, nothing out of the ordinary, slipped gently into fifth (around a ton or so) and within a few seconds the drive disappeared, revs climbed gently....very similar to what I read in this post...

http://www.lotusespritforum.com/forums/ind...amp;hl=5th+gear

Carried on to my destination a few miles on in 4th at around 60. Stopped, started again and headed for home. There seems to be an extra whining sounds from the gb but maybe I',m imagining it.

Anyway - having had a look last night through the threads I'm now planning how to get this sorted as painlessly as possible.

I'm guessing on a full rebuild/replacement but I'm curious if there are other outcomes (ie, cheaper!) first.

Cheers for any help

Charlie

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

If you're lucky it may just be a weak clutch. Put it in 3rd or 4th and press on the clutch while keeping on the gas a bit then release the clutch. The tach should immediately go back to the proper RPM's for the speed. If the tach is somewhat slow to return then it's the clutch

Share this post


Link to post
Share on other sites

Or simpy put the car in 5th and see if you can push it without much resistance, if you can when it's in 5th but not when it's iin 4th then it's a gearbox issue rather than clutch.

At least 5th gear is in the end that can be removed without having to strip the whole bax so you can partially inspect it without removing it from the car.

Share this post


Link to post
Share on other sites

Agree with above, sounds very likely to me. Clutch problems usually show themself mostly in the highest gar first due to the fact that more torque is required to generate the acceleration. Think of how much harder it is to pedal your bike when your in its highest gear, yes you can go a lot faster but it takes much more effort to increase the speed accordingly.


Chunky Lover

Share this post


Link to post
Share on other sites

At first I thought, "First Top Gear is going and now another motoring program bites the dust."

I would have thought that, if 5th gear had failed, the engine would have revved freely when you put the car into 5th. Revs rising gradually sounds like a clutch problem to me.


S4 Elan, Elan +2S, Federal-spec, World Championship Edition S2 Esprit #42, S1 Elise, Excel SE

 

Share this post


Link to post
Share on other sites

Ah - what I mean is that I didn't floor it after the change up - was anyway about to get to a 120(70) limit.

There is no contact with the drive in 5th - its as if the clutch is depressed. The first couple of times trying to get it into 5th felt like there was something contacting at the end of the lever and then nothing.

Called R&B who are pretty sure its the primary shaft.

On the plus side it gives me a chance to sort out the 2nd gear synchro as well as squander my Chrimble bonus 4 months early. What joy!

Share this post


Link to post
Share on other sites

Charlie,

Sorry to say that ... but I bet that you snapped your main-shaft-5th-gear-overhang.

Its quite a typical failure ... may happen.

Usually it happens on the Autobahn at high speed when you lift the throttle to 0% and then put your foot down again to 100% within 1-3 seconds.

Its easy to verify. Just remove the rear gearbox covver and have a look.

You will see that 5th gear came lose (= the shaft snapped and the gear is still attached to the fragment).

Time to remove the gearbox and rebuild it.

Marcus


Marcus

Share this post


Link to post
Share on other sites

Hi Marcus,

Yes I heard a long time ago thats how to break it so I NEVER came off then hard on to the throttle again. I considered maybe the revs dropping with the upchange into peak torque maybe finished it. I'll try take a look but I think you are right.

The clutch operation was never my favourite but the 4th gear accelerates normally enough.

Am considering to get the upgrade.... feels like a trip to the dentist....

Share this post


Link to post
Share on other sites

Roger: I'm going for the upgrade. The point of the car is to make it last as long as possible so it makes sense not to take a short cut with the GB.

Paul. Me neither! Cheers for the idea. Your car sounds interesting, are there any pics?

Share this post


Link to post
Share on other sites

All done.

Primary shaft as suspected. Not the cheapest thing to have to repair but at least the job was very well done. Big thanks to Steffen at R&B... smile.gif

Before

post-1141-1254856769_thumb.jpg

After

post-1141-1254856903_thumb.jpg

Is the new main shaft came from GTO Engineering?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...