Engine & Gearbox Mounts - Replacement in Situ

[RedCat7]

Any tips for doing this on a 2011 Sigma SV 5-Speed?

Engine mounts appear straightforward using a trolley jack for engine gearbox support.  Tacking care not to lift the engine more than a few mm so that the exhaust doesn't clash with the side skin.

What about the gearbox?

One at a time while the rest remain tight or loosen them all off, replace and then tighten up in one go as though doing an engine install?

The reason for replacement is that I had an engine vibration through the steering wheel at higher revs.  Had it for years but it's got worse and the engine mounts appear a little perished.  Nothing is touching the chassis or steering column than shouldn't be.

Jim

[Scotland North AR]

Hi, mine's a 2009 SV. The passenger side mount sheared off where the box section meets the flat plate which is bolted to the engine. This was down to lack of penetration on the weld. Caterham sent me a new mounting FOC under warranty to fit myself (live near Aberdeen so couldn't take the car back practically). There was a posting a few days ago from someone else with an engine mount gone at a different weld. Lesson learned, wire brush off the welds and look for signs of cracking at all welds before putting back on.

Top tip, when you are putting the bolts back into the engine, put them nearly all the way in with fingers as they are small threads and easy to cross thread if forced in. Torque up to correct value with no weight on the bolts i.e. still on the jack.

 

[Geoff Brown]

If the engine mounts appear to be perished & overly soft to the touch then change. A further check with the engine running is to inspect the top of the rubbers & see if there is a noticeable seperation of the threaded insert from the rubber. The natural engine vibration should show this up. 

Gearbox mount could be a tad difficult in situ due to the chassis cross piece that supports the mounting....best of luck!

[Jim 123]

I'd say that the gearbox mount is do able but you need to take the tunnel cover off.  You will need a long socket extension to get down to the 4 bolts that fix the cross bracket to the chassis from above.  Chances are you will need somebody to hold the corresponding nuts from turning underneath the car.

If your problem is a steering vibration within a rev range, have you had a play about with the angle of the steering column?  There is a chance that you either have a touch condition where it enters the pedal box or a near touch.  You might also want to check that the gearbox is not contacting the LH chassis lower longitudinal.

[paul richards]

Are you sure vibration is not due to wheel balance?

[RedCat7]

Yep.  The vibration is engine speed related.  At say 60mph I'd feel a buzz in 3rd but not 5th. 

[Geoff Brown]

'Buzzes' in Sevens can come from any where. I had an engine speed related buzz that appeared to be somewhere on the near side & I though it was maybe the skin vibrating in harmony but no it was just the passenger seat rail bolts slightly loose.

[RedCat7]

Yeah, in the past I thought the exhaust was rattling but it turned out to be the seat runner handle on the chassis rail.  Which I cured with a strip of sticky backed foam.

In this case though it's a silent buzz felt through the steering wheel.

 

[Nick Chan]

Hi Jim,  

Its easy to do all of the engine mounts including metallastic bushes with a jack under the sump (protected by a piece of wood).  Gearbox is very straightforward too and can all be done from underneath - I loosened the large 19mm bolts into the metalastic bushes and the engine mounts on to the block with the jack under the sump and then undid the large bolt holding the box to mount and then undid the smaller bolts holding the g'box mount to chassis.  Using another trolley jack under the middle of the gearbox to get a bit of a lift and the mount came free.  It was a surprisingly easy job even on an S3 and should be real easy on an SV!