Noises, normal or not?

[Glynh]

My 12month old 360S SV arrived on Thursday and I love it. Bearing in mind I'm a convert from a Morgan Three Wheeler, (so fairly used to bangs, knocks and whines) what should I accept as normal from my Caterham 7? 

I have a whine from the rear, (most likely the diff) and also a singular knock coming through the prop shaft tunnel on take up in lower gears. Also a knock from the rear when I hit a bump in the road.

 

 

 

[Jonathan Kay]

I'd start with the easy bits:

• Check the prop shaft joints and bolts.

• And the bushes and play on the A frame in the rear suspension.

Have you found your local group? That should provide access to some expert ears. : - )

Jonathan

PS: If you'd like a copy of the appropriate Assembly Guide and Owner's Handbook then please send me a Private Message with your email address. 

[Benton]

Every Caterham I've driven with a BMW diff has had a whine to some extent, typically starting around 55mph. My Sierra diff certainly appears less whiny, however that could be because it's masked by the gear noise from the sequential gearbox!   

Knocking from the drive train can be caused by a number of components, any slight take up stack between the components will be amplified due to the chassis design.  It's certainly worth jacking the car up and checking the various components but don't be surprised if you don't find anything obviously wrong!

[GulfSeven]

Check the diff carrier bolts are torqued too.

[ScottR400D]

Neither of the two BMW assemblies I've had have whined, though there was much clunking and banging until I got rid of the Titan LSD. 

I have heard others, though, that have screamed and I'm sure there are all stages in between.

I would suggest that the answer to your question may be that you might expect some whine, though it's not really normal, (if not uncommon) but the bangs or knocks shouldn't be there.

I hesitate to ask but is it an LSD? 

 

[Glynh]

Standard BMW diff. 
I have found that the nylon washers are missing at the De Dion tube / A frame / metalistic bush mounting, how critical are they? 

[AndyButters]

Hi Glyn

I have similar issues with my 360S S3, which I built as a new kit and has been on the road a month.  I've driven Caterhams before and don't remember the drivetrain rattle and whine but maybe that's selective memory or they had another diff.  I plan to find some time to put it back on the stands and check all the propshaft, diff, and driveshaft connections for torque and any play.  There is definitely a clunk on occasions when I release the clutch when changing gear on the move.  There's also a occasional clunk or rattle when going over bumps which I'm thinking might be the A frame, diff, or play in the driveshafts.

I've got the BMW diff which is marked as LSD even though that was an extra which I didn't order.  Initially I was really pleased as I'd debated whether to go for it but shied away on cost grounds.  Having read lots of comments since about the downsides of the noise and wear/need for rebuilding I'm beginning to wonder if it was such a 'gift'.  Would anyone go as far as recommending I push Caterham to replace it with the standard diff that I actually ordered?

 

 

[Glynh]

All sounds very familiar Andy, I'll check my BMW diff! Mine was a factory build. 

[ducatidentist]

I've got a 3 week old factory built 420r which has a noticeable whine between 50-60mph regardless of which gear it's in. Above 60 I guess wind noise makes it less noticeable.

No significant knocking or grinding from the diff even in low speed manoeuvres. Much quieter than that 360r I test drove for an hour before ordering mine.

[mantioras]

I have a similar clonking noise from the diff area when changing gears, especially 2nd-3rd. Sometimes a single clonk happens when cornering, as if some metal ball changes position and bangs into another sidewall of anything holding it. My mechanic tells me it's tripode bearings in the driveshaft, which has some play. 2009 Ford diff and gearbox.

[J888PRB]

Glyn

All pretty normal noises you hear about on the forums and nothing usually to fear.

The rear knock over bumps I used to have... and was an easy fix with replacing the nylon washers on the rear A frame.. You may find replacing that rear bush with a poly bush is a worthwhile investment rather than changing the washers every 5 minutes. I got a powerflex one and was a simple enough swap and not had the noise come back.

If you are LSD then the rest of the noises are not unusual. all sound amplified in these cars (compared to morgan) as the drivetrain is solid mounted to the chasis. 

 

[Mike-360R]

Yes, my 360R home build has exactly the same noises as mentioned above- diff whine from 50 to 60ish and clonking from what sounds like somewhere around the diff / back of the gearbox / prop shaft. I would say the noises have probably got slighlty more frequent and louder the more I've driven it - not too noticeable post IVA but 1,400 miles in an definitely a bit worse. Clonking seems to be in the lower gears as previously described - mostly when not under load. Checked the diff bolts and carrier bolts just today following advice from GulfSeven at the track day on Monday. While access was difficult to check the actual torque setting from within the boot, a visual inspection of the paint marks on all bolts gave me confidence none of the bolts have started to unwind. However, I will check everything over once the car is on axle stands at the end of the month for a full fluid change and service.

[Nigel B]

My car has no knocks, clonks or whine, so I don't think you should accept such things as 'normal'.

In my experience, whine from a diff tends to be caused by an incorrectly adjusted crown wheel & pinion.

Chasing down such noises rather than simply accepting them is well worth it in the long run.