Starter Motor Replacement

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david painter
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Re: Starter Motor Replacement

Post by david painter » Sat Jun 23, 2018 8:24 pm

If its a inertia Starter you want listing sounds and reads as correct. Have you measured your voltages as I posted above?
Dave

blueplasticsoulman
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Re: Starter Motor Replacement

Post by blueplasticsoulman » Sat Jun 23, 2018 10:10 pm

Yeah it's an inertia starter that i need. The Ring gear is chamfered on the gearbox side.

I'm a little confused as according to the Haynes manual, the 2m100 was the pre-engaged type that was fitted. There must be a 2m100 pre-engaged and Inertia available. Haynes manual says that the Inertia type starter was M418G so actually i think that's the one that I need. Trouble is, there's only a few i can see on the likes of ebay (£150ish), and when you read some of the descriptions, it only lists the Marina 1300 and not 1800. Yet the same starter from another seller lists it as being suitable for a 2.3 Vauxhall Magnum. There's also 9, 10 and 11 tooth versions.

Im just reading conflicting information really as the guy who built the starter motor i now have seemed dubious as to whether an Inertia starter would do the job.

I'll jot down the voltages tomorrow.

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mickthefitter
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Re: Starter Motor Replacement

Post by mickthefitter » Sat Jun 23, 2018 10:50 pm

Autobooks manual I have, first published 1972, my edition fully revised 1978, covers Marinas Mk1&2, 1.3, 1.8, TC, Special, HL, GT, Van, Pick-up, 1971-78. Has this information about starter motors -

1.3 standard - M418G (I assume inertia)
1.3 cold climate - M35J pre-engaged
1.8 standard - 2M100
1.8 cold climate - 2M100

With the latter two for the 1.8 not being specified as pre-engaged I assume they were inertia - which suggests the book was not updated thoroughly in 1978 to cover Mk2s.

The torque at 1000rpm of the M35J is given as 4.4 lb/ft and the 2M100 7.3 lb/ft.

I've got a Haynes manual for 1.8 models up to 1978 that in the Mk1 section mentions the M418G inertia (that the Autobooks manual reckons was only fitted to 1.3s) and a pre-engaged 2M100. Turn to the chapter 13 supplement for Mk2s (like my car) and the ONLY starter motor mentioned is the M35J, which mine has, but which is generally reckoned to be weak for a 1.8 auto! So its no wonder you are confused as the workshop manuals don't seem to be gospel as to what was used.

david painter
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Re: Starter Motor Replacement

Post by david painter » Sat Jun 23, 2018 11:03 pm

Inertia type starter. Original Unipart number GXE4418. Cross Reference 25609, 25659, 25555, LRS00289, 25598, GXE4418, LRS289 Lucas motor type number M418G.
Dave

blueplasticsoulman
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Re: Starter Motor Replacement

Post by blueplasticsoulman » Sat Jun 23, 2018 11:46 pm

lol@Mickthefitter. An interesting read and sums up my confusion perfectly.

Also in the Haynes manual, it says "Both starter motors are interchangeable and engage with a common flywheel starter ring".

Not interchangeable really are they. It's either one or the other depending on which ring gear is fitted.

Would you then deduce that i require the M418G Inertia then? Seems that David Painter has cross referenced and reached that conclusion.

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Kilroy
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Re: Starter Motor Replacement

Post by Kilroy » Sun Jun 24, 2018 1:00 am

I have used an Austin Princess 2 litre starter motor to good effect when converting my 1700 Marinas to 2 litre.
They are physically longer and electrically more powerful than those fitted to 1700 Marinas.
I imagine they might bolt up to an 1800 engine but could not guarantee it.

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mickthefitter
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Re: Starter Motor Replacement

Post by mickthefitter » Sun Jun 24, 2018 9:10 am

My Autobooks data doesn't give a torque figure for the M418G at 1000rpm....maybe it cannot achieve 1000rpm! However of the three motors mentioned in that book, for something called 'lock torque', the M418G has the highest figure, 17 lb/ft, as opposed to 7 lb/ft for the M35J and 14.4 lb/ft for the 2M100.

As regards interchangeability and the Haynes manual, you know more than I do as apart from when I had to have my Morris Marina starter motor rewound last year, the only time I've removed starter motors in the past was during a handful of clutch changes I've been involved with, and I've never noticed chamfered flywheel ring gear! Dave's information, Haynes mention of the M418G in relation to 1800s and the highest 'lock torque' figures in the Autobooks manual would suggest you wouldn't be far wrong with one of those, though.

Just an idle thought, if you cannot source one elsewhere...I wonder if it might be worth giving David Kingerley of Obsolete Car Spares a ring? He bought the closed Earlpart stock, although that doesn't mean they had one...but if he holds a lot of old stock parts, he might have one from elsewhere. http://www.obsoletecarspares.co.uk
From time to time I also use Fittapart Parts For Older Cars (Mansfield) https://www.carparts-direct.co.uk/fitta ... older-cars although it is safe to say they can get hold of generic parts like wheel bearings and shock absorbers more easily than make-and-model specific parts, it's just that Martin who runs the place has a lot of old parts catalogues and a list of suppliers he rings around to see if he can get what you ask for. Unfortunately when I needed a Marina exhaust back box, even though it was still listed (the middle box hadn't been listed since 1999) none of his suppliers held any and wouldn't be ordering any because they needed a minimum order quantity of about 20. But he's worth knowing about just in case.

david painter
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Re: Starter Motor Replacement

Post by david painter » Sun Jun 24, 2018 9:12 am

MGB Ring Gear part no
1G2874 RING GEAR, (10 3/4” diameter) 1 1964-67,
12H2900 RING GEAR, (11 1/2” diameter) 1 1967 on
Marina Ring Gear part no
22G1634 Ring Gear Marina 1800
These part no are taken from BL parts manuals. The Marina part no is from October 1976 on, that is the publication date in my MK2 catalogue. I do not have one for MK1 I have googled it and found two separate listings for it fitting Marina 1971-1974. My 1800 Special 1977 uses a pre engaged starter part no 13H8611 (M35JPE)Parts manual says fitted 1975 on
Dave

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mickthefitter
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Re: Starter Motor Replacement

Post by mickthefitter » Sun Jun 24, 2018 10:21 am

I feel sure the M35J, which has been said should be fitted to the 1300, was probably fitted to later 1800s as a BL cost saving exercise. If it's a smaller motor it must have saved a few pennies per unit, and I bet somebody came up with the suggestion of giving it a go on the Mk2 1.8, found they could get away with it, and fitted that instead of the more powerful 2M100.

blueplasticsoulman
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Re: Starter Motor Replacement

Post by blueplasticsoulman » Sun Jun 24, 2018 10:48 am

Haynes manual i have lists the torque.

M418G

Lock Torque: 17 lb/ft with 420 amp load
Torque at 1000rpm: 8 lb/ft with 320 amp load

2M100

Lock Torque: 14.4 lb/ft with 463 amp load
Torque at 1000rpm: 7.3 lb/ft with 300 amp load

blueplasticsoulman
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Re: Starter Motor Replacement

Post by blueplasticsoulman » Sun Jun 24, 2018 2:02 pm

Well, disaster!

From an engine that turned over by hand when we bought the car, to an engine that now needs ratcheting round with a a socket and breaker due to been tight. Dunno whats gone wrong! I've been barking up the wrong tree.

I think it's safe to say that the starter will be good as although it struggles, it still manages to get round consistently. Albeit rather slow.

Engine out then!

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mickthefitter
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Re: Starter Motor Replacement

Post by mickthefitter » Sun Jun 24, 2018 2:29 pm

:thumbdown: Oh dear!

blueplasticsoulman
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Re: Starter Motor Replacement

Post by blueplasticsoulman » Sun Jun 24, 2018 3:13 pm

Oh dear indeed!

I'll start a "Readers Project" thread and get some pictures of the process/progress up.

david painter
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Re: Starter Motor Replacement

Post by david painter » Sun Jun 24, 2018 4:11 pm

If you have been swapping starter motors around and that's all you have changed. Remove the starter and see if the engine frees up power outputs of both types of starter are similar.
Dave

SLOW ITAL
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Re: Starter Motor Replacement

Post by SLOW ITAL » Sun Jun 24, 2018 7:07 pm

david painter wrote:
Sun Jun 24, 2018 4:11 pm
If you have been swapping starter motors around and that's all you have changed. Remove the starter and see if the engine frees up power outputs of both types of starter are similar.
Dave
I wondered about that David,
Whether the pinion on the new starter had the same number of teeth as the old one ,
Ive been given a replacement with 10 teeth when the old one had 9. It was noisey when engaged & slower
In time might have jammed up altogether.
Gil.

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