Starter spins but Engine doesn't: Bench test/shimming

[The_Handier_Man1]

From: chicisles  (Original Message)
Sent: 7/23/2005 9:29 AM

Having read the threads on starter problems, I think the bendix on my starter may be the reason it does not spin engine. I have a 1986 Winnie with the 474 Chevrolet.  I need some advice from the other side of the big pond on how to remove starter for bench test,is this necessary?



From: denison
Sent: 7/23/2005 12:33 PM

What is your starter doing, or failing to do? Does the starter spin? Does it turn the v8 engine at all?

The Bendix assembly in your starter has the function of allowing the starter to spin the engine, and when the engine itself starts up - the gear teeth on the starter will rotate freely on the starter output shaft, and allow the flywheel to turn faster, without trying to spin the starter to destruction.
I dont know what would be involved in removing a starter from a 454, as my winnebago has a dodge chassis, but once I had the starter off, I would be inclined to have it rebuilt, or buy a rebuilt one, rather than re-install a possibly defective or old starter.
And where on the other side of the pond are you?



From: chicisles
Sent: 7/23/2005 3:13 PM

The starter is spinning but the engine is not turning. I am in Scotland.



From: denison
Sent: 7/24/2005 9:50 PM

I think you will definitely need to remove the starter to check out that problem. I can think of several things that might make it malfunction as you describe, and all of them involve removing/dismantling the starter to fix - or getting it rebuilt.
For starter removal; I am going by what the 87 Chevy Light Truck service manual says: Disconnect the battery; disconnect the wire to the starter solenoid, remove any heat shield and bracing bracket. Remove two bolts, two nuts and washers, and don’t lose the shim. !! Then remove starter. The manual doesn’t say whether this will be easy, or a frustrating chore. Perhaps you can let us know.
Not too many of us have the newer Winnies like yours, with the Chevy/Workhorse chassis. Hence our lack of experience with the 454. A friend nearby has a Sunflyer motorhome from the later 1980s, on the Chevy P30 chassis, so I can at least crawl under his to see what you might be up against. Me and my digital camera.
By the way; he failed to lubricate the grease fittings on his driveshaft. A U-joint failed last summer on the interstate halfway to Florida, with the result that the vibration cracked the bell housing of the transmission!



From: firebug9-1-1
Sent: 7/27/2005 1:30 AM

On my 454 you have 3 bolts,  2 wires on the solenoid, and it drops out on your head. Very Very easy, The starter has a clutch built in to it, and I had to have mine rebuilt, It costme about 45 bucks..  I didn't even have to jack it up, crawled under behind the passenger front tire...oh and no shims on mine...



From: chicisles
Sent: 7/27/2005 8:25 AM

thanks for your input.took the starter out today,straightforward.no need to drop exhaust.no sign of shims. the cast end of the motor had snapped so pinion was not being held secure. I wonder why this happened, maybe lack of  shims new starter on the way any advice on shim sizing welcome



From: denison
Sent: 7/27/2005 11:22 AM

The shimming procedure looks simple “on paper”. You have the starter reinstalled… partly anyway. You make up a feeler gauge, .020 inches in diameter, about 3 or 4 inches long, with the last 1/4 inch bent over to 90 degrees. This is used to measure the spacing between the outer part of a tooth on the flywheel, and the bottom of the space between teeth on the starter pinion.
It doesn’t explain how you are able to reach the area where the teeth are, but maybe you can do that with the splash shield removed from the bottom of the bell housing, I don’t know.
You have to hold the starter pinion extended toward the back of the vehicle, with a small screwdriver stuck in a slot that is supposed to be in the bottom of the starter casing, close to the bell-housing.
You want that spacing, between the end of the tooth on the flywheel and the mating “space” between the teen of the starter pinion, to be at least .020 inches (.5mm), but not more than .050 inches (1.3mm).
#24 AWG wire is about .020 inches, or .51mm.
The manual says the shims are .3mm thick. My experience is that the shims fall out while still stuck together, so I have never known how many there were. I just put it back together with the shims that fell out, and hope it is right, but it is probably worth doing it properly on a vehicle you want to be reliable on vacations.



From: chicisles
Sent: 8/3/2005 3:19 PM

New starter in. I put in one shim 1/32 to give some clearance. Any  of  you guys interested in a rig swap say in two years time. Mine is here in Scotland, ideal for visiting Ireland, England and Wales and even Europe. Im thinking about a period of say,  eight weeks. Just a thought at this stage. I would like to explore some of the USA.



From: Chicisles1
Sent: 11/6/2005 10:42 AM

Still having starter problems, when first installed it is fine after a few cranks it starts to get noisy as if the teeth are not meshing. I have experimented with shims but it seems as if the alignment is changing when cranking. What about the mystery bracket to support the weight of the unit. I notice there is a protruding stud at the rear end of the starter to suggest a bracket should be used, but where does it connect to on the chassis.Can you buy the bracket as a part or is it worth making one as I live in Snowy Scotland.



From: ClydesdaleKevin
Sent: 11/15/2005 2:20 PM

I don't recall seeing a bracket stud when I replaced our starter, but then, Winnies might be different then my Futura.  Did you check your flywheel teeth for wear when you have the starter off?  Put your rig in neutral with the parking brake off and the wheels chocked (removing the spark plugs will relieive backpressure and allow you to turn the flywheel easily), and use a screw driver to carefully turn the flywheel while you look in the opening where the starter would be (assuming you have the starter removed for troubleshooting).  Use a flashlight (Don't they call them electric torches over there?...lol), and look at all the teeth...mark one with chalk so you know you've gone full circuit.  Expect some wear, but not GROSS wear.  Look for missing teeth, especially many missing teeth in a row.  You might have a worn-out flywheel.

Assuming the flywheel is in good shape, its possible that the rebuilt starter you have was rebuilt incorrectly.  It might have too much play in the bendix/shaft/etc.  If your flywheel is good and you can't resolve the issue with shims, then take the starter back to where you bought it, and exchange it for another...it has to be a bad starter at that point!

All that aside, good to meet you, cousin!  I was born here in the states, but both of my Grandparents on both sides of my family were "right off the boat", Scottish immigrants to this country!  MacGregor on my father's side, MacKenzie on my mother's side.  There is also some Frazier on my dad's side mixed in, and Muir and MacGowan on my mom's somewhere way back in the family tree...lol.  I've visited Scotland quite a few times when I was still in the Naval Submarine service, but only had the opportunity to visit a few great aunts and uncles around Glasgow and Edinburgh.  What part are you from, and from what clans do you hail, if you don't mind me asking?

Anyhow, I would LOVE to take you up on your offer to exchange rigs for a while, but it would be quite a few years before that could ever come to fruition...we are engaged with a rather busy travelling schedule.  If you do make it over here, and you happen to be in an area that I happen to be in, ales and Scotch is on me!

Kev



From: Chicisles1
Sent: 11/16/2005 1:03 PM

Kev, thanks for the info, getting there I think, the shimming and torque seem to be critical. I'll have a good look at the flywheel.  I live in Perthshire and I am a Macdonald,not the fast food variety.   Chas



From: denison
Sent: 11/16/2005 4:50 PM

   .  I would not have thought the proper shims were super critical, and once the starter is bolted in, it shouldnt move around much in cranking.   But then, you have a nicely mysterious problem with that starter.   If you turn the engine around using the teeth of the starter ring, look to see if the toothed ring is twisted or bent.  You should see a short section of the ring where the teeth are noticeably more worn than elsewhere - about 2 inches of more shiny and battered teeth.  Thats because after an engine is broken-in, it always stops turning in about the same position: And when you start it the next time, the starter gear initially contacts about the same few teeth.  This is not usually a problem unless the vehicle is started Very often, like a delivery truck, or the vehicle the wife uses to take kids to soccer and swimming events.