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MG Midget and Sprite Technical - gear shaft and link assy -wiper motor

help please

whilst the car is just sitting there I thought I do a few of the little jobs

I'm changing the wiper motor gear shaft and link assembly but all is not going well

I read up first from the Workshop manual then the two different ages of Haynes I have, all three publications are a bit short on details and/or to understand as a non-mechanic

I've managed to disconnect the wiper rack from the wiper motor (by being brutal with the c-clip that holds the link arm on) and I've got the wiper motor out of the car

15 minutes of struggling and I've manage to get the c-clip off the bottom of the gear shaft

now here's the first problem the current gear shaft had only one thin cup washer on the gear shaft, the new set comes with two thin cup washers and two thin flat washers - what goes where and in which direction as regards these washers

and when I put the wiper motor and rack back together do I really have to install the link arm assembly and then the small flat washer and c-clip with the motor in postion and having the to try to get the c-clip on when it will be at the furset point under the wing with a gapping black (?)cavity ready to swallow a small black c-clip
Nigel Atkins

anyone?

before I pack it away for the night
Nigel Atkins

nigel i moved the wiper motor on my rebuild as after dropping a spanner into the chasm of the wing i could only see myself doing it again !

But i was using all new parts, bending the tube that carries the worm drive as gently as i could whilst keeping the height of the motor in alignment i found to be easier with the motor sited over the passenger footwell, as opposed to tucked over to one side as per original.

as i bought all the bits, it fitted together without any problems, so sorry cannot help with the washer, c clip issues you have.

attached pic may help show you

p bentley

On mine, there is enough slack in the connecting arm that it can be lifted at the distal end to unhook it from the bush on the end of the spiral rack cable. You just need to undo the little hex headed screws and lift the flat cover plate off.
C clips shouldn't give you that much trouble Nigel. Easiest is to use the ends of snub nosed pliers, pinching against the end of the shaft both for fitting and removal.
I don't know about the position of all your washers.
There. Isn't a lot of maintenance that can be done on the motor itself.

The best gains are had by cleaning old dried grease from the rack tube, re-greasing and getting the alignment right. Best modification l have is a 120 degree gear to give a better sweep of the wipers.
Guy

Remove wiper arms.
Unscrew nut that holds cable housing to motor.
Remove motor, pulling cable out of the housing whilst still attached to the drive.
Do whatever, including clean and lube drive and cable.
Reverse.

FRM
FR Millmore

And you could also turn the wheelboxes through 180 degrees (if you've previously marked the spindle position) and turn the drive cable over and so utilise the unused part of the assembly. Lots of good gen on this site
http://www.mgbstuff.org.uk/electricstext2.htm#wipers
The wiring switch connections are correctly illustrated and explained (unlike the SVC page)
Derek Stewart

Thanks for all your replies to answer them now –

pb,
if I was starting I would have it in a better position but it has the washer motor and reservoir and main earth wire there now so a bit of extra work to move them and the rack and boxes were new 5 years or so ago

Guy,
there was plenty of slack with the old connecting arm when I broke the c-clip off, the c-clip on the end of the motor gear drive was more a case of not being able to see well, I must admit I didn’t think of the squeeze and push with pliers I was using cheap precision screw drives to clean the black muck off the black c-clip and to get it off which I eventually did after running a small surprising sharp screwdriver down the top of my finger

problem was when I took the old gear drive out it only had the c-clip on the bottom and one snapped dished washer, I hope this is the cause of the judder, the new set had a c-clip and two flat and two dished washers

I eventually found an exposed diagram of the wiper motor and it should c-clip and flat washer at bottom and one dished washer in middle, so one spare dished washer

the motor is reassembled but not back installed as I’m not felling well (tough!)

Derek,
I read the stuff there and Paul put turning his wheelboxes didn’t help on that occasion for him and as mine aren’t that old and they look a pain to get at I’ll leave be this time but good info on there and lead from you, I actually found the exposed wiper motor diagram on SVC via elsewhere but didn’t know the switch was wrong, I only have one speed although the motor is two speed
Nigel Atkins

FRM,
didn’t think of that because I assumed (always a silly thing to do) that on withdrawal the outer metal sleeving would drop down and be difficult to get back into position and that the rack would be awkward to thread back

but I liked the logical simplicity so I’ve just pulled the rack out and see the sleeving attaches to the wheelboxes for some reason I thought it didn’t the very end sleeving is missing from mine but I think I can live with as I’ll be able to at grease there when required

when I put it back in is it best to use dry PTFE lubricant then grease from wheel box apertures or grease the whole rack before reinstallation please?

I’ve packed the wiper motor gear drive with grease already
Nigel Atkins

Nigel-
Secret: It's in the book!
The tubing outer casing is flared at the ends, and trapped by little slots in the wheelbox covers. If they are not trapped, the whole affair works poorly. Same principle of a Bowden cable relying on the casing relative to the core; the motion comes from the relative change of length between the two - one must be anchored. The casing acts as bearings to locate the rack relative to the wheelbox gears; if some of it is missing the rack will jump teeth, or bind as it tries. The casing tubes are exactly the same as similarly sized steel fuel pipe, so cut a flared end 3" stub to replace the missing bit. You need to loosen or remove the cover to get the flare in the slots. Put the rack through after all the tubes are in place correctly.

Just grease up the rack as you install it. A once in ten years deal. If the cable is difficult or sticky, some idiot has kinked a tube and you need to replace it.

You do not remove the wheelboxes, just turn the spindles a half or third of a turn from where the rack left them as it came out. It will then go in a half turn off from that - hey presto, new teeth!

FRM
FR Millmore

FRM,
your suggseted method wasn't in the three books I looked at, well not where I looked

I've absolutely no idea where I got the idea that the tubing was loose fit and I now see I totally misunderstood the turning of the wheelboxes - it would be funny if it wasn't sad, no it is funny

I don't think I should do these things when I'm not feeling too good or post about them proving I'm an idiot but I'm not a much better when well

I could have just looked under the dash but no I didn't, I thought I knew

rack looks good, tubing has a tighter bend than I'd have put but it worked fine for 4 years so it can stay

thanks for all the info

thanks to pb, Derek and Guy (I'd already got the 110 gear and fitted it before I saw your advice so that'll stay now too)

I wonder what caused the dished washer to snap, I guess I might find out if it happens again but hopefuly (not certain) next time I'll remember the tips I've been given here
Nigel Atkins

felt better today so decided to finish the job

to cut a long story short

the wiper go the wrong way and park on the wrong side

gave me a right fright when they started to wiper the bonnet

is it me have I touched something I shouldn't have?

have I been given the wrong gear shaft?
Nigel Atkins

Did you remove the wheelboxes?
Guy

no I just turned them by finger to move the teeth

I was just going to look up there was a nut on the of the motor that was loose and I just turned that figer tight
Nigel Atkins

So you didn't remove the rack and wheelboxes from the car then?
Guy

I took the rack out as suggested by FRM and grease it up

I wonder if I done something with the park switch without realising but I don't see how

there was a slight bit of of movement when I switch on I think but not sure now I think I though the thing was parking but I'm even doubting if it happened now

on diagram the nut was a lock nut to thrust screw but I didn't touch the screw, I don't think I did anyway I'm starting to feel as if I don't my a from my e
Nigel Atkins


Nigel-
I do not have one in front of me, so this is memory.
If you have a square motor, then the round gear cover gets turned to adjust park position.

I think you have a round motor, so the park position is fixed by a bump on the "bottom" of the gear. So compare to the old one.

Some motors can be reversed in rotation by assembling the main case 180deg out from where it was, relative to the plate carrying the brushes. That would also reverse the relationship of the park and drive bits on the gear.

Be certain to turn the wipers ON and then OFF, to get to PARK, BEFORE you fit the wiper blades!

If the nut you tightened was in line with the motor shaft, it is a thrust adjustment. The screw should be just gently tight (zero end float) then backed off a bit, and the nut locks it in place.

Should be lots on this on Paul Hunt's MGB site.

FRM
FR Millmore

yes round body, I meant to check bump on bottom of gear between old and new before fitting but I forgot

I did test movement before fitting arms/blades, the slight movement I guess (if it happened) wasgoing to park

I switched on without arm/blades to make sure movement of the wheelboxes was smooth and it was but I didn't notice diection of move,ent

when I fitted arm/blades and switched on they flick to bottom edge of screeen, I got out to lift arm off screen and like two nasty snakes they slithered across my bonnet

I only tighten nut with finger as I recall and didn't turn screw

I can only think I've been given the LHD gear shaft as I don't think I checked under it or can't remember now
Nigel Atkins

Remove both the wiper arms. Switch the wipers on and then off again and let spindles move to the park position, checking to see which way they rotate as they move towards park. (It should be clockwise) Then re-fit the wiper arms so that they lie in their normal parked position along the bottom of the screen. That should fix it.

If the spindles rotate anticlockwise before coming to a halt, then either the motor is turning the wrong way as FRM describes. Or the wheelboxes have been inverted, which is why I asked if you had removed them.
Guy

viewing from the driver's seat they park anti-clockwise

it's raining now so would be an ideal time to test blades if they were going in correct position

the only other thing I can think of is that I've put the gear shaft in 180 degrees wrong but I thought I was sure that the connecting rod was fully back and not fully forward

in fact I'm (almost) certain I put the gear shaft and connecting rod in the same position they came out because it was so obvious I didn't do a drawing

wheelboxes weren't removed
Nigel Atkins

I meant that if you watched the spindles they rotate clockwise towards the park position. I assumed that you would be outside the car, leaning in over the bonnet and looking down on the end of the spindle to check which way it was rotating.

Now you say that the wipers are parking anticlockwise when viewed from inside the car. This is correct. But earlier on you said -
"the wiper go the wrong way and park on the wrong side"

So do you now mean that you have fixed it? What was the fault?
Guy

now I'm even more lost

it was raining and dark so I sat inside the car with the door open and I reached round the other side of the windscreen to feel which direction the spindle went

looking from the driver's seat the spindle starts from the pasenger side and goes clockwise - to park it goes anti

park is with the arms/blades on/towards the passenger's side - that's not how I remember it before this sorry saga started
Nigel Atkins

as I put earlier I don't think I fully followed my own advice and fully checked the new part before fitting, although I meant to I might have forgot to check the position of the bump stop on the gear shaft

I'm hoping the bump is 180 out as I've found it just pulls out and can be clipped in 180 degree away in the other set of locating holes

so motor out again which will required the help of my very relucant assistant who's already said my lovely rachet ring spanner doesn't fit properly another chromed nut for me to find she must have been holding it at an angle as the points of the nut are now missing some chrome

metal luggage shelf has to come out to get at one nut as the shelf didn't fit properly it has some thin wooden spacers, 10 screws there with the back two knuckle scrappers

never mind all should be easy as I've had some recent practice
Nigel Atkins

Nigel-
As stated, I have not a car or motor to look at, but one of us is around the bend.
Is the motor not under the bonnet, with two bolts through a rubber pad into welded on nuts securing a retaining strap?
No chrome nuts or lovely helpers needed, no parcel shelf fiddling.

The gear must stop at the extreme of travel in one direction, and 180 out from that for opposite hand cars.

If there are two possible positions for the bip which operates the park switch, that's all the possibilities.

You cannot assemble it wrongly in any other way, save the possible motor reversal. Since I discovered the motor reversal many years ago (blower did not work worth damn all), I always mark everything for correct assembly, so I've not had the problem, nor any cause to deliberately reverse one.

FRM
FR Millmore

Hi FRM,
no you’re not round the bend but I am, so far in fact it’s a circle

yeap it’s the rubber strapped round bodied motor but it’s not on captive nuts a previous owner has drill holes and has loose washers and nuts, possibly its positioned further into the wing (fender) than normal, I looked for the possible captive nuts but they’re not near by and as I didn’t want to kink the bundy tube I put back as found, possibly the previous owner had to place it there because of how he’d done the bundy tube that connects to the motor

one of the loose nuts is at the back corner of the metal parcel shelf, with help I can get it off with the parcel shelf in position but not on again without a lot messing around which my wife quickly bores of, I can’t reach both the bolt and nut at the same time as that bolt is situated well under the lip of the wing

the wrong motor location probably explains why the bundy tubes put the wheel boxes just slightly off straight so I was attempting to get a better wheelboxes to screen angle for the wiper arms by me loosening the chrome nuts that holds the bezel wheelbox bush then me inside using brut force and slight twist of gease covered wheelbox bush whilst my wife tightens the chrome nuts (cackhandedly) she insisted on using the ring ratchet end of the ¾” spanner which meant it was close to the paintwork and her knuckles to the windscreen

after 20 years of being outside in the wet and/or dark I’m more than fed up with messing about with cars and she’s a lot more so – one night many years ago I had her in the boot with a lead lamp trying to figure something out those things are out of the question now

fishing out the old gear shaft from the bottom of the second rubbish bag (it’s never in the first is it) and looking at it and finding the park bump can be moved 180 degree made me realise that although I paid enough for the correct dedicated gear shaft I’d got a kit that had options hence also the extra washers

as I said it’s my fault for forgetting to check the new part was exactly the same as the old part as I preach to others – of course the existing part fitted can be incorrect – as in the missing washer on the bottom of the shaft that spreads the c-clip fixing across the body instead of just the internal bush which possibly allowed movement for the internal dished washer to snap, maybe

when I take it all out again I expect to find the connecting rod to be in the position the old one was but with the bump stop 180 out – all my fault but next time I’ll save a bit of money by buying the same kit from elsewhere
Nigel Atkins

well all back out and back in again

sure enough the bump stop was 180 degrees out

I will try to follow my own advice in future and fully check the new parts before installation

now the bonnet catches on one of the wiper arms so I'm going to try Bob's (?) trick of the two washers under the front part of the hinge plate to lift the rear of the bonnet(?) I hope I've got that right

it can't decide if it wants to rain heavey here or not so that I can either do the bonnet or test the wipers in the rain
Nigel Atkins

Sorry, I'm tired and didn't read everything, but maybe this will help. I know it's a different topic, but talks about taking the motor apart.

http://themgdoc.com/windshieldwiperpark.htm
don g

thank you for that

the link does refer to USA MGB but is still usefull

it does miss out the bottom washer and dished washer inside on mine and the fact the cam can be removed from the cog and put 180 over on the cog rather than moving the whole cog (on mine at least)
Nigel Atkins

This thread was discussed between 31/05/2012 and 14/06/2012

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