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MG MGA - Wiper motor removal

Hi
I havent posted for a while but am still alive and kicking! I am now trying to get my Mk2 back in running order.

The wiper motor is not working at all. Power is getting in, and switch is earthing ok. So thought I need to remove the motor and take a look inside.
I have looked at archives and on Barney's site but seem to have come to a halt. Removed wipers arms, electric connections and bolts securing motor body. I started loosening large nut holding cable to motor body, expecting it to release and slip up cable, but it doesnt.
So I tugged on the motor hoping it would come free from cable, or come out with the inner cable, but it doesnt!
Didnt want to force it. Am I missing something, or should I open wiper box in situ?

Thanks, Graham
g Victors

Graham
First you have disconnect the wires, then you unscrew the setscrews that fasten the motor bracket down to the bulkhead.
The motor should now be free from the bulkhead and you should now be able to lift it up an inch or two. If it will not lift away at all there must still be a setscrew that has not been unscrewed.
Next you have to completely disconnect the large nut holding the drive tube and slide it away from the motor.

Now after removing the wiper arms you should be able to pull the motor out, the flexible drive rack will pull out of the tube. You should see the wiper spindles spinning as the rack pulls past them.

Hope that helps

Colyn
c firth

Colyn,
Thanks for those very clear instructions.
I have done exactly as you say, except when I loosen the large nut holding the drive cable, the cable just doesn't come free from the motor.
Just can't work it out. I don't need to release anything at the other end of the cable, do I?
Or if I take off the lid of the motor, at the cable end, do you think it would help?

Thanks, Graham
g Victors

Graham,
Undoing the nut only releases the drive cable pipe, not the internal flex drive cable which is connected to the drive arm from the cog of the motor underneath the metal cover. As Colyn says, having undone the nut holding the PIPE (not the drive cable which is internal to the pipe),lift the motor and draw it towards the front of the car (you may have to hold the pipe with the other hand to hold it), leaving the pipe in place, and draw the drive cable through the pipe (again, as Colyn says, observe the wiper spindles rotating). You could struggle to take the cover off and remove the circlip which secures the earth tag and the drive arm in situ, but you won't have good visibility or access. Funnily enough there was an article on these motors in Classics Monthly recently which has some good photo's.

regards
Colin
Colin Manley

Thanks Colin,
You guys are obviously made of stronger stuff than me. Tried with all my might but it wouldn't budge. But took top plate, circlip etc off easily enough and now have it on work bench.
Not sure why it wouldn't come out the conventional way, maybe that is contributing to the motor failure.

Strangely enough, playing around with the meter I also discovered with all power off, I had a reading of the disconnected green lead and earth of just over 2 ohms. Very odd, as that should be the live feed. Something else I need to research.

In meantime, I have to put my toys away as grandchildren about to arrive!

Thanks for the help, Graham
g Victors

Graham,
Now you have the motor out, try and move the flex drive cable fore and aft in the car and see if it is free and not restricted so that the wiper spindles rotate. You could have worn carbon brushes in the motor but it does not take a lot of extra friction in the flex drive arrangement for the motor to be unable to overcome it. The only places for the flex drive to encounter friction is in the support tubes and the wiper arm wheelboxes.

regards
Colin
Colin Manley

Graham, now that you have removed the motor you could reconnect the wiring to see if it operates. If it runs then you know that the flexy-drive rack or the wheel boxes are the problem and they need to be removed for checking.

If it doesnt run then obviously need to fix the motor but also you still need to remove the rack and wheel boxes as they may be seized up and have caused the problem with the motor.
Colyn
c firth

Hi
Managed a quick 5 minutes to carry out those checks.
Can't seem to get the drive cable to move at all. I am assuming that the large nut on the end (that looks cross threaded to me, see pic) that won't come off, wouldn't restrict the inner cable movement.
But to add to my woes, I bench tested the motor and the best I can get is a hum! So Colyn may well be right that the siezed cable has caused a problem to the motor.
Sadly the car has been little used over last year or so,and certainly not gone out when there was a hint of rain. So maybe it's all siezed up.
Thanks for your support, it does help tremendously. Graham

g Victors

Graham,
Here are pictures and info that I sent to Barney after I disassembled, cleaned and reassembled my wiper motor. http://mgaguru.com/mgtech/electric/et217a.htm

You may need to loosen the LH wiper wheel box clamp that is holding the curved section of pipe so you can at least get it out of the car. That way, you can determine if the threads are crossed.

Jim
JL Cheatham

Jim that is brilliant! So very descriptive and well laid out. A valuable contribution to our MGA fraternity.
And thanks once again to Barney.

Barry
BM Gannon

Hi
Thanks for postings. Thought I should report back for archives, if nothing else.
Managed to remove wheelboxes and entire cable assembley from car. A bit fiddly but it came out eventually. Once removed, the inner cable slipped out from the end & middle outer cables, but was completely jammed in the outer cable nearest to the motor. All my muscle power wouldnt shift it, so no wonder the motor has also given up the fight. Released it by attaching my electric drill and slowly spinning it out. But it wont go back beyond the bend in that nearest outer tube!
So I have a motor that doesnt work and an outer cable that wont take the cable. So I guess I will buy a new outer cable, and see if I can get the motor repaired somewhere as that is beyond me. If anyone can recommend, be good to hear.
Regards, Graham
g Victors

Graham,
It sounds like the tube was bent and the inner collapsed and trapped the flexdrive cable. Be careful with buying new outer support tubes. There are instances where the union to connect to the motor has been fitted to the wrong tube, resulting in a tube that is 40mm too long between the wheelboxes and 40mm too short from the motor to the first wheelbox.


regards
Colin
Colin Manley

Colin
Thanks for the advice. I will make sure I check it out before buying
Regards, Graham
g Victors

Before buying a new one or giving the old one to a pro shop, you might consider fixing it yourself. If the armature is burned out it might be beyond reason, but brushes and bearings are easy enough to replace.
Barney Gaylord

Colin
I think you are right. I phoned Moss and the motor nut is attached to the shorter of the two tubes (excluding the very short tube)
In fairness, they were very helpful. They said the one with the nut measured 13inches and the other one measured 14 inches.
I was expecting it to be about 15.5inches and 13.75 inches respectively.
I can use the two without nuts from my present set up and I guess it is possible that the one they supply with the motor nut will fit if the bend is shaped differently. What do you think?
But am very concerned to hear from Moss that I have to bend that piece myself, as am concerned if I don't get it just right the inner cable will be trapped once again and I am back where I started. Is there a trick?

Or I was thinking is there any reason why I can utilise my existing outer tubes. And just cut out the curved section with the internal obstruction and replace it with rubber tube and hose clips?
The stupid thing is my wipers only generally get used when I go for the annual MOT

Barney. Thanks for your comments. I think the armature winding has gone. Brushes etc look as good as new. I have sourced a reconditioned unit.

Thanks, Graham
g Victors

The clearance between the wiper drive cable and the 5/16" Cu-Ni tube is not very large and if the curved section nearest the motor is kinked or bent in any way the tube jams against the cable.
Mine was like this and I tried different ways without success to correct the tube. In the end I made a new one from tubing I had left over from replacing the fuel tube from the tank. Fortunately this tube was supplied bent into a coil of the correct diameter so all I had to do was to cut a suitable length.

Forming the flare at the motor end was a bit tricky ......................Mike
m.j. moore

Graham,
Yes the Moss kit has the union fitted to the wrong pipe - ask me how i know!! Moss are looking into this now - it is as simple as the union being fitted to the wrong pipe. The interconnecting tube (between the wheelboxes)is approx 380mm long and in the kit, the union is fitted to the tube that is 380mm long, i.e the wrong tube.

You wont be able to make the incorrect motor to wheelbox tube from the kit fit - it is way too short and you would have to make such an extreme bend in the tube to make it fit that the inner drive would jam.

I bent a smooth curve on my own tube very gently with the inner drive cable in place and it was OK. I used 8mm pliable copper gas pipe.

I would not use rubber tube etc as you will be presenting two shoulders for the inner drive cable to chatter or jam against.

Moss have come to the same conclusion as me in regard to the union fitment and i will post an outcome when i get one from Moss.


regards
Colin
Colin Manley

Hi Colin,
Its disturbing to hear that Moss are aware of this problem but said nothing when I queried it. They just said they had sold a high number of these units since the previous inward delivery without a single complaint so they must be correct!
My measurement of the centre pipe is a little different to yours. My central interconecting tube is 34.5cm in length and the curved one is 41cm.
What also confuses me is that Moss said all three tubes are supplied straight and from what Mike has said, bending it could be problematic.
I guess I need to source alternative tubing, though no idea where. But putting flares on the end will be a challenge for me.
Thanks, Graham
g Victors

Graham, plumbers have a copper tube bending device you could borrow? -- a spring that fits neatly over the tube to be bent so that the tube will not collapse as you gently bend it. I used one today fitting a new gas line into my house. They are relatively cheap, or -- maybe your friendly local plumber could bend it to a paper template -- would take only two minutes!
A plumber could also flare the end.

Barry
BM Gannon

Graham, I've just had a look and I've got plenty of the original size 5/16" tube left over and still coiled so I could send you down a length if you want

I made the flare on mine by spinning a conical fixed centre in my lathe and pushing the tube end against it by hand. It gave a bit of a flare, not as much as the original, but it doesn't need to be much because the conical nut is a very close fit with the tube.

Unfortunately I sold my lathe and accessories last year after I'd completed my restoration so I can't repeat this. However if you have anything conical you could probably tap it into one end to flare it a bit................................................Mike
m.j. moore

Barry, Thanks for the advice and Mike, that is very kind of you, thank you.
But since my last post I have managed to clear the blockage and get the inner cable moving a little in the tube, so have left the tube to soak in WD40.
Once I get a working motor, I will see if it is sufficicntly free to allow the motor to do its job as that will obviously be the easiest thing for me.
I am not sure what jammed it but am guessing it may have been hardned grease.

You guys on this forum are so helpful. I wish I was a bit brighter so I could reciprocate!
Regards, Graham
g Victors

> I sold my lathe

I know what each of the above words mean individually, but together, they make no sense.

-Del
D Rawlins

WD40 is the last thing to use to free it up. Use white spirits and then the grease will be softened. WD40 will just leave a sticky deposit that won't help at all.
dominic clancy

> I sold my lathe

I know what each of the above words mean individually, but together, they make no sense.

-Del


Wow! I knew that execution of the English language had suffered on it's way across the Atlantic but I didn't appreciate that it's comprehension had taken a knock as well !! ................................Mike
m.j. moore

You Brits and Aussies have it so easy. On a LHD car it would have taken this number of postings just to get the wiper motor out of the car! LOL.

Peter.
P. Tilbury

Thanks Dominic - good advice
Regards, Graham
g Victors

Hi
To cut a long story short I now have a wiper motor that runs and just need to follow those helpful words, "re-install is a reversal of the above".
Is there a trick in getting the outer tube and wheel boxes in position?
The wheel boxes are very tight to get in place, but to do that whilst attached to the outer tube is seemingly impossible. And to assemble the wheel boxes to tube in situ is also not simple for two reasons.
First access to the locking screws on the wheel boxes is very difficult as (at least in my car) there are supporting brackets in the way. And secondly, it seems that for the outer pipe to marry up to the wiper motor, the pipe needs to be under quite a lot of tension, to get "round the corner". Add this to the fact that the wheel boxes need to be manipulated to get into place and the answer so far has just been a lot of very bad language!
Any tips would be very gratefully received, Thanks, Graham
g Victors

Hi
All now sorted,
And thanks again for the help. So just for the archives, in case anyone else has the same problem......
The easiest way I found to reassemble was first to cut much larger slits with a hack saw on the heads of the small screws of the wheel boxes so they can take more force from a screwdriver. As a screwdriver was the only tool I could use to access the screws in situ. And as for access, I drilled a hole through the dashboard support arm to allow me to get the screwdriver to the screws.

And finally don't make my mistake and fit the wiper motor in place first unless the outer pipe has been bent absolutely precisely. Instead, fit the pipe to wheel boxes first, and then when all tightened up, tension the pipe to fit on the motor. Mine needed a lot of force to line up.
Don't worry if the wiper blades don't park in the right place, Barneys site explains all as u just need to spin the disc on the parking section of the motor, which can be done easily enough in situ.

Graham
g Victors

This thread was discussed between 06/03/2015 and 24/03/2015

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