75ZT Community

A couple of weeks ago a member asked me if I would help him replace his starter motor contacts and plunger as his R75 Diesel 2004 was having trouble starting, the starter motor was sticking now and again and with winter coming up would only get worse.

I agreed and we set about removing the starter motor from his R75 diesel once we had removed and replaced the contacts and plunger the car started on the button.

This got me thinking I will replace my own even though I had no trouble with starting as a preventive measure as my own car FL 1 had done the same mileage 83,000 and was roughly the same age albeit a couple of years younger, I did this and to no surprize they were pitted but not to bad.

I mentioned this to my son and we decided to change his as well while doing his MGZT diesel 2005, it gave me the chance to take photo's which i am sharing with you hopefully this should help members whom want to repair their starter motor, if it is sticking or as we did as preventive measure or if the car is having trouble staring and the starter is the fault.

The kit can be obtained form the link below, I picked my kits up as the seller carl whom is a nice chap lives not to far away, the link below is for the diesel but petrol 2.0/2.5 are also available, as is the ones for a the 1.8 he will also take calls if you wish to go down that road.
http://www.ebay.co.uk/itm/251755645921? ... EBIDX%3AIT
His direct sales are http://www.startermotorkits.com please feel free to say Steve ( Arctic ) referred you.

Right after the introduction lets get down to removing the starter motor, remove the engine cover and the air duct from the slam panel.




You then need to remove the negative lead from the battery 13mm spanner, this is the thick black cable if this is all new to you Fig 1

1

Once the battery as been disconnected you will now need to remove the two battery cable leads from the starter motor, also an electric spade connector wire on the starter solenoid which is just pulled off, the cables are removed by undoing the 13mm nut in the pic below Fig 2
2

Remove the spade connector first Fig 3
3

Undo the 13mm nut next Fig 4
4

Once the nut is loose remove with your fingers so as not to drop it into the engine bay below, on to the under tray Fig 5
5

Now remove the cables Fig 6
6

To make it more easy I found it better to remove EGR (Exhaust Gas Recirculation Valve) four Allen key/10mm bolts and the jubilee clip and set aside the intercooler hose, Fig 7/8
7

8

You will now need to remove the two starter mounting bolts noting that the upper bolt secures an engine earth lead, this is 13mm and a deep socket is best I found, the bolt can be found under the trunking holding some wires. Fig 9
9

Using the socket loosen the upper bolt holding the earth lead Fig 10/11
10

11

With the upper bolt loosened/removed you can now remove the lower bolt/nut you will need a 13mm ring spanner and a 15mm ring spanner for this Fig 12
12

Once you have remove the nut you can slide out the lower bolt Fig 13
13

If you have not removed the upper bolt beforehand but only loosened it ? now is the time to remove it, leave it to dangle Fig 14
14

This pic shows where the bolt resides Fig 15
15

Next remove the clip holding the coolant pipe Fig 16
16

This will allow you to move the coolant hosepipe to one side, Fig 17
17

Now the coolant pipe/hose is out of the way it gives better access to extract the starter motor Fig 18
18

Lift the rear of the starter motor a turn it upwards towards you Fig 19
19

The starter motor should come clear of the engine that is phase one, now you have the starter motor in your hands you can progress to replacing the starter contacts and plunger Fig 20
20
Cheers Arctic

Phase two of replacing the starter motor contacts and plunger to a diesel R75 MGZT.

Now the starter motor is on the work bench you can start to dismantle it to replace the damage contacts/plunger or just as a preventive measure as I/we did.
Your repair kit should have two contacts and a plunger along with a short instruction leaflet.



First remove the 3 x 8mm bolt/screws holding the rear metal cover Fig 1/2
1

2

Remove the rear back plate cover inside you will see the plunger Fig 3
3

With the back plate removed slowly pull out the plunger noting the spring train this as it is re-used Fig 4
4

As you can see even though my sons MGZT starts on the button first time the plunger as started to pit and corrode nothing unusual after 10 years and 75,000 miles of use. Fig 5
5

Once the plunger was removed we could also see the condition of the contacts which were also pitted, Fig 6
6

First work on the left connector a 14mm ring spanner is needed to undo the nut Fig 7
7

Next remove the small washer and plastic insulator retainer Fig 8
8

Behind the insulator you will find a small rubber O-ring keep this safe as it needs to be re-used after Fig 9/10
9

10

Now you have the nut,insulator & O-ring removed you can extract the connector, push it through slowly inwards and out Fig11
11

Keep this safe as the copper bolt needs to be re-used Fig 12
12

The left side should now look like this Fig 13
13

Now you can turn your attention to the right contact this as a rubber cover and two nuts holding the copper bolt/connector into the starter pull the rubber cover back Fig 14
14

The first nut is a 12mm undo and remove keeping it safe for re-use Fig 15
15

With the nut removed you can pull off the lead Fig 16
16

Now remove the 14mm nut Fig 16a
16a

Next is the little metal washer and plastic insulator Fig 17
17

Last remove the rubber O-ring again keeping it safe as it will be reused Fig 18
18

Now carefully take a look at the contact inside of the starter motor as it as a wire connected to it, note how it fits between the copper bolt head and the contact Fig 19
19

Carefully remove the bolt from the unit Fig 20/21
20

21

With both copper bolts removed you can clean out the dirt and dust with a small soft brush, note on this starter motor the insulator as broken so that will have to be replaced also. Fig 22
22

Phase two is finished all that remains now is to replace the new connectors and plunger. Arctic
http://www.ebay.co.uk/itm/251755645921? ... EBIDX%3AIT
http://www.startermotorkits.com

Phase Three replacing the new connector and Plunger before re-fitting the starter back onto the car.

First the left hand connector will need to be spilt as this as slotted serrations which hold the connector to the bolt and the new contact fitted onto the bolt Fig 1
1

Now with the old plunger and the new plunger side by side remove the spring and replace it onto the new plunger Fig2/3
2

3

We can now re-fit the right copper bolt with the contact making sure you add the wired connector between the bolt head and the new copper contact Fig 4
4

With the wire between the bolt and the contact push the bolt back through the side of the starter, keeping the contact square Fig 5
5

Now add the rubber O-ring Fig 6
6

Next the plastic insulator and metal washer Fig 7
7

The 14mm nut can now be fitted do not over tighten the nut Fig 8
8

Then fit the lead and the 12mm nut Fig 9/10
9

10

Once again do not over tighten the nut Fig 11
11

You can now fit the left hand side bolt and contact, push it through and add the rubber O-ring Fig 12
12

Fit the plastic insulator and metal washer making sure the insulator locates into the round hole Fig 13
13

Add the 14mm nut do not over tighten Fig 14/15
14

15

The new plunger with the spring can now be re-inserted into the starter Fig 16
16

The back plate is now fitted to the starter Fig 17
17

Do not over tighten the three 8mm bolts trying to remember how tight they were when you removed them Fig 18/19
18

19

The Starter is now ready to be fitted back on to the car phase Four. Arctic

http://www.ebay.co.uk/itm/251755645921? ... EBIDX%3AIT
http://www.startermotorkits.com

Now the starter is repaired it can be fitted back onto the car Fig 1
1

Feed the starter into the space between the coolant hose cog/teeth first you may have to twist it a little to get it into place. Fig 2
2

Once you have the cog into the opening you should line it up ready to accept the bolts. Fig 3
3

Now the starter is lined up and inserted you can refit the lower and upper bolts. Fig 4
4

Fit the lower bolt first with the bolt head to the left of you, and nut to the right Fig 5
5

Now fit the upper bolt with the earth lead and tighten it up Fig 6/7
6

7

Add the nut to the bottom bolt and tighten up with the ring spanners 13mm & 15mm Fig 8/9
8

9

Last of all re-fit the battery leads to the side of the starter left lead first then the right one Fig 10
10

Add the nut and tighten up to secure and cover over with the rubber cover Fig 11/12
11

12

Do not forget the electric push connector

The last job is to fit the battery lead to the battery, then re-fit the EGR, air duct and engine cover job is done cheers Arctic.

Thank you Steve for making these detailed how-to guides.

Jürgen wrote:Thank you Steve for making these detailed how-to guides.

Hi Jürgen.
My pleasure as I like doing them, see you in October

Arctic wrote:see you in October

Just two weeks to go

photo above will be reinstated asap as I am redefining my photo albums cheers Arctic.

Why not also change your brushes & bushes at the same time, they'll also be well worn by now & its a very simple matter when you've got the starter motor on the bench, the same goes for your alternator, change your brushes & bearings at about 80,000 miles & save yourself having to fork out for a new stator & windings because the bearing have collapsed & smashed everything up, its a standard thing that I always did for caterpillar earth moving equipment, it not only saved money but also saved breakdown time in the bush, common sense.

Ted wrote:Why not also change your brushes & bushes at the same time, they'll also be well worn by now & its a very simple matter when you've got the starter motor on the bench, the same goes for your alternator, change your brushes & bearings at about 80,000 miles & save yourself having to fork out for a new stator & windings because the bearing have collapsed & smashed everything up, its a standard thing that I always did for caterpillar earth moving equipment, it not only saved money but also saved breakdown time in the bush, common sense.

HI Ted.
Please feel free to add any photos you have of changing the brushes to the thread I am sure it will be most appreciated by all owners and members cheers Arctic.