Dodgy diff.?

Post by **Dryad** » Mon Mar 14, 2005 2:57 pm

I have a 1968 4-door saloon. When I partially take my foot off the accelerator whilst going along, so that the car is on the cusp of slowing down, there is a kind of clunky rattle from the rear of the car (I think), which stops if I accelerate again. Is it likely to be the differential, or the universal joints? Or both!

Also, there is some 'play' on the steering, which clunks when I go over potholes in the road. I assume it's the steering rack, but is it likely to be dangerous to drive like this?

I've only had this car for a week, and it's my first Minor, so I don't really know what noises etc. to expect, or even what is normal for a Morris!

Any advice appreciated. Thanks.

Post by **Willie** » Mon Mar 14, 2005 7:47 pm

The position you describe would be when there is no load on the
drive train. Hopefully this would be a worn Universal prop shaft
joint although a worn one would usually cause some vibration
when driving along. If it was in the diff unit it would normally be
damped considerably by the EP90 oil.....have you checked the axle
level????? Steering gear...there are many causes of noises,
start with oiling the steering rack. on the toe board inside the car
on the passenger side you will find a rubber plug, under this is the
nipple for oiling the rack with EP90 oil, normally a maximum of
12 strokes with an oil gun. Check that and we will talk you
through the next stages. Another thought, the rear of the prop-
shaft is bolted to the diff unit by 4 bolts/nuts, check that these are
tight.

Post by **bigginger** » Mon Mar 14, 2005 7:52 pm

Steering rack total capacity is only half a pint, BTW - I just happened to read that, by coincidence

Post by **rayofleamington** » Tue Mar 15, 2005 9:11 am

The gearbox is another potential source of vibration when coasting. First thing to check for the gearbox is if there is a fair bit of cross axial (sideways) play in the front end of the propshaft. The front end of the prop should fit snugly in the bush at the rear of the gearbox, therefore play indicates a worn bush. The gearbox should be filled with engine oil - if someone has used EP90 instead, then the gearbox life will be reduced.

Post by **Dryad** » Tue Mar 15, 2005 10:02 am

Thanks, I will check these things at the weekend. I did manage to quickly measure the amount of play in the steering this morning; it measures at 16mm (5/8") when marking the outer edge of the steering wheel and then turning it until the play stops. It seems like excessive play to me.

Post by **paulb2** » Tue Mar 15, 2005 1:42 pm

Where can you obtain an Oil Gun?

Post by **Cam** » Tue Mar 15, 2005 2:03 pm

They are usually called grease guns and most car accessory shops sell them. I know Machine Mart does. Halfords probably does too.

or the hand pump type:

See:
http://www.machinemart.co.uk/search.asp?q=grease+gun

Post by **rayofleamington** » Tue Mar 15, 2005 2:06 pm

Where can you obtain an Oil Gun?

1) get a high quality grease gun
2) take the grease out of it and pump the nozzle empty
3) put oil in it and bleed it
4) use it to oil the steering rack
5) empty the oil out again as it is likely to drip out over time making a mess

The diff can be filled using the flexi tube normally found on the EP90 oil container.

These type of containers with the flexi tube attachement are very useful for filling the gearbox so if/when its empty, swill it out and fill with engine oil ready to top up the gearbox (don't forget to mark the container up so you know which one has engine oil, not EP oil)

Post by **Willie** » Tue Mar 15, 2005 2:11 pm

YES.. 5/8" play is too much on a rack and pinion. There should
virually be no free play at all at the wheel rim. First check that
the steering wheel retaining nut is tight, then check the nut and
bolt at the base of the column. There is an adjustment possible on the actual pinion free play and, of course, you will
have to check the track rod ends for any free play. If you can grasp
the steering wheel and rock it left to right then the felt bushes
in the column are worn which makes the whole car feel 'sloppy'.

Post by **Dryad** » Tue Mar 15, 2005 3:42 pm

I thought it didn't seem right. Thank, Willie. I'll try and check it tonight.

Post by **bmcecosse** » Tue Mar 15, 2005 5:30 pm

The rattle on bumps is most probably worn swivel pins - these can pull out when very badly worn - causing great inconvenience. Get the front suspension thoroughly checked as soon as possible. The clunk could be prop shaft (most likely) of perhaps worn out bushes in the rear springs. This is not as urgent as the front rattles - get them sorted out first !

Post by **rayofleamington** » Tue Mar 15, 2005 8:01 pm

Suspension clucks tend to be worn suspension rubbers, but if the front suspension wasn't greased often enough then worn trunnions are likely too.

Post by **Peetee** » Tue Mar 15, 2005 9:10 pm

I had a rattle from the front of the car too. I replaced all the suspension bushes, then the uprights and trunions but to no avail. The steering rack was to blame and was replaced by a reconditioned unit. This more or less solved the problem but the odd, quieter knock could be heard from time to time. There was also still some play in the steering too.

Post by **Onne** » Tue Mar 15, 2005 9:17 pm

I only get cluncks if I go over speed bumps with more than approx 5mph or more(depends on the bump)

Post by **Dryad** » Wed Mar 16, 2005 3:03 pm

I checked the steering column bushes - they're fine. As was the steering wheel nut, and the nut and bolt at the bottom of the column, so it could still be the rack, but I'll check everything else first. Anyone know how long it takes to replace a steering rack?....

Post by **Cam** » Wed Mar 16, 2005 4:15 pm

Depends on how good you are with a spanner. I have done it before and the hardest part is getting to the little clamp securing nuts under the toe-board. It does not take THAT long though.

Post by **Willie** » Thu Mar 17, 2005 6:48 pm

It is a straightforward job but you have to be careful when fitting
the new one that you have the rack in the mid position with the wheels
in the straight ahead position when you re-engage the steering column.
After fitting you obviously have to have the tracking checked within
a very few miles. If the rack is at fault then the 'clunking' is
usually due to worn rack dampers.

Post by **Dryad** » Mon Mar 21, 2005 12:43 pm

Still haven't had a chance to check the UJs, but I've now checked everything on the front, and it's definitely the steering rack that's faulty. I also uncovered another horror; the nearside lower suspension arm was cracked! Fortunately, and thanks to Bryan Gostling, I was able to go and pick one up and fit it an hour later.

But life's just not that simple, because now there's another problem; the car now veers slightly to the left if I let go of the steering wheel, and I'm sure the steering wheel is now not 'straight'. I mean that the wheel looks like I should be turning slightly to the left, rather than going straight ahead. I suppose this must have something to do with replacing the lower suspension arm. Any ideas?

Post by **rayofleamington** » Mon Mar 21, 2005 1:04 pm

I suppose this must have something to do with replacing the lower suspension arm. Any ideas?

Well normally replacing the pressed steel part of the lower arm is unintrusive so I struggle to see how it could be related, but it would be wise to check everything went back on correctly (Eg the spacer in the right place for the tie bar bracket etc..)

Are the front brakes dragging slighty or are the tyres non-matching? (even those faults rarely create this fault - in fact this one is fairly hard to create)

Morris Minor Owners Club

Dodgy diff.?

Dodgy diff.?

slow down

Oil Gun

steering

steering