Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing BTR axle end float

Hi Folks

This thread is timely as I'm also beginning to have trouble with the BTR axle fitted to our 04 Roadster. There is a knocking as though gears are not fully in mesh.

Strangle enough it only manifests itself after a longish run on the motorway when I leave and slow down/stop at the roundabout. When driving on non-motorways/dual carriageways there's no issue as, I assume, the constant changes in lateral forces keeps things more or less in place.

I popped into my local dealer who had never come across this issue before. I assume there is no need to replace the wheel bearings at 30k miles but is it worth replacing the 'pressed steel retainer'. If so, has anyone knowledge of where to get this individual part? I would have thought that dealers would be familiar with this issue and have a suitable remedy.

Also, what damage will there be if the problem is not addressed.

Thanks in anticipation.

Are you sure this is not coming from the LSD? If it sounds a bit like a loose wheel at low speed I would first change the diff oil and make sure it contains friction modifier.

Thanks Dave - Seems like the cheapest first step: can you please suggest which oil and what friction modifier?

I got a clunk the rear hub Castle Nut had backed off onto the split pin. this will result in wear between the Hub and the shaft and woodruff key.

Once you get the clunk and if you have hub movement, you will need to remove the hub, and then lap the hub back on to the shaft to take up wear (belt and braces). Check woodruf key for signs of wear replace if necessary.

Roady - different people prefer different oils but I use Morris Lubricants - which the factory recommend.
Axle oil is Lodexol 80W140 with friction modifier included.
If necessary I add a slosh of extra friction modifier sourced from Demon Tweeks.

In my early days I used semi-synthetic diff oil as recommended in the handbook, but realistically fully synthetic is arguably better.
http://www.morrislubricants.co.uk/products/auto/gear-transmission-oils/lodexol-xfs-80w-140.html

Other brands are available.
http://www.castrol.com/en_au/australia/products/cars/axle-and-universal-fluids/syntrax-80w-140.html

http://www.redlineoil.com/product.aspx?pid=37&pcid=4

I am hearing bearing noises in My '63 +4-4Str. It has a BTR axle sourced new about 50,000 miles ago. I checked the front wheel bearings and U joints. Sort of sounds like an aggressive tire tread. Alignment is OK. Only noise when wheels are turning. Takes about a half a mile for the noise to start and then gets louder. After about 5 miles the noise gets as loud as it is going to get. Any experience/ideas on how I can confirm if it is a rear wheel bearing.

Button
Seattle

If you can get to it ,give it a squirt from a oil can[ any oil].See if it goes silent.Will only last a short time. But will show its a bearing.

No way I can see to do this. I did jack up one rear wheel and spin the wheel while I used a stethoscope on each wheel bearing and pinion bearing. No obvious noise.

Button
Seattle

Regarding Rear Axle Lubricants mentioned above . I queried the factory about the preferred lubricants back in 2009 their reply is below:-
Dear Mr Smith,
 
Your car is a 1999, which would mean that the axle in your Plus 8 is a BTR.  The lubricant recommended for this axle can be Castrol SAF-XA, or Mobil SHC80w-140ID.  These are the recommended lubricants for this axle.
 
At the Morgan Motor Company we currently use Morris’ oil lubricants and we use an 80/140 synthetic, which is known XFS 80/140.  We have used this for many years now.  It also contains the additive to which these axles need.  Our recommended interval for change is 100,000 miles or 6 years, whichever comes first.
 
We hope this answers your question, but please feel free to come back to us of you have any other queries,
 

My car's 12 year's old now but I doubt it's had it's oil changed once during that period let alone twice (30,000 miles to date). Talking to the owner of a Plus 8 over the weekend suggests that the noise I've been experiencing (not so much a noise but banging like an outhouse door) is cured simply by an oil change.

I haven't had the opportunity to replicate the conditions of heat/long motorway run etc that caused me to have the car 'relayed' to the dealer so perhaps I'll have to wait until next summer to be 100% sure it's now OK.

Not sure if there's an emoji for fingers crossed