84 FW Southwind; 454 Chevy; flexplate/starter issues

[raccoonman]

i replaced the starter back in the early spring, noting at the time that the teeth on the flexplate looked questionable, and for a while all was well and the rig started up readily... for a while.
the starter seems to have found a rough patch of teeth and will not spin the engine. i can clearly hear the bendix throw the drive gear into place and then "CHUNK", and a high-pitch whine from the starter. no spin. climb under, loosen the mounting bolts a bit, give the starter a whack, tighten the bolts back up, turn key, same thing, MAYBE an eighth of a turn of the engine....
soooo... it seems that i shall have to replace the flexplate AND the starter....
bit daunting, yes, but not impossible. what i want to know, because i am NOT a Chevrolet person, is whether or not i need to put the shims between the starter and block, or how many, or even HOW to determine this, while i'm doing this job?
this ought to really be fun. (note genuine sarcasm, not your usual bland stuff)

[whem2fish]

Been years since I had to shim one yes I have more than a few you will have to google this one best I remember we used a pin gage, drill bit or what you have you put the gage inbetween one pinion and ring gear need to remove the spring in the solinode the shim till proper gap

[pwf16129]

i'm a chevy fan from way back but unfortunately their starter setup leaves something to be desired, if memory servers right it is a one.eighth steel pin that comes with a new starter but the surest way it to go to the parts house and get them to copy the installation instructions for you.
depending on the casting on the block you could use whole shims or half shims to get it right some times on the inner side sometime the outer.
and it depends on the starter nose housing.
but the pictures on the paper work are pretty good then it is just a matter of patience but worth the aggravation.

[ahicks]

I spent some time working in a Chev dealership in the late 60's/early 70's. Ran across this a few times then. I remember the starter thing being a PIA, but not much more. I did however become quite the flex plate change out wiz. I learned not to drop the trans, but rather slide it back after installing several longer bolts to allow me to do that? Usually had to put a jack stand under the oil pan to hold the engine in alignment. Maybe everyone does this, but thought I'd pass it on in case it might help. FWIW -Al

[whem2fish]

Great thought

[raccoonman]

that's exactly the idea i was going to use; longer bolts to give me some hand room up in there. seems like plenty of room over top of it so it won't hit anything moving it backwards. what i need, really, is to get the darn thing running ONE MORE TIME so i can get it up on the concrete drive....
if this rain doesn't let up (rained nearly every day this month and Isaac isn't helping matters) i shall have to get it licensed as a yacht...

[JimM68]

try turning the flywheel with a screwdriver pushing against the flexplate teeth to get it to a good spot, then crank her over.

You don't need to shim them very often... A full shim will increase the clearance, half under the outside will make it tighter. Checking the clearance is a PIA, there is no room to get anything in there. It most certainly is not a one EIGHT INCH anything,more like a piece of paper. I generally go by sound...

Hopefully you can find a truck starter, they have an iron nose.

There is supposed to be a metal strap from the nose of the starter to the block, very important to hold the starter in alignment. Make sure you put it back, get one if it is gone.

The starter bolts are very important too. The factory bolts have a knurled section just above the threads that is a tight fit in both the starter nose and the block. REPLACE THE BOLTS! There may be a long bolt and a short bolt or just 2 long bolts. You can still get the long bolt at a GM dealer (DO IT!) the short bolt is discontinued, you can get a reproduction at napa but they are not as good, do not get your long bolt there, only at the chevy dealer.

454's also had a heat shield around the starter, again, highly recommended to use one or get one if it is gone.

I like the long bolt thing. You'll need 1 jack under the oil pan of the engine, and a second (wheeled) jack to walk the trans out. You will probably have to disconnect the fluid cooler lines, have something handy to plug those holes in the trans, and a pan to catch the drippings that will come out of the hoses and radiator cooler.

The trans will need to come pretty far back 3-4 inches anyway. The driveshaft and linkage will need to come out (oil will run out of the back of the trans, best to leave the front of the driveshaft plugged in if you can. There will be an electrical connection or 2.

Probably will be easiest to just rent a proper trans jack. Would be really bad form to lose control of the thing and drop it.

Remember to unbolt the torque converter from the flexplate. Make sure the torque converter stays on the trans, it will want to slide off.... oily mess if it does.
The flexplate bolts come from GM with a threadlock substance on them. Best to use new GM bolts, ok to clean em good and use blue locktite.

That's about all I can remember.

[ahicks]

The torque converter is notched to engage the front pump. If that torque converter is moved away from the trans far enough, then turned, getting those notches lined up with the pump can be, well to be kind, tedious....

Bottom line, do your level best to keep the converter snugged up against the trans....

[raccoonman]

i can attest to the ease of front pump destruction; i did it with a C6 years ago when installing it. thought i had the pump drive ears engaged, let the TC slip a little, and didn't check it again, just bolted it up. car moved about three feet and puked ATF all over.

sad thing? it happened again when i sold a good C6 and the customer installed it wrong. i ALWAYS double and triple check the TC position now....

i think i might be able to drop the dust cover and turn the flexplate/crank to a better spot, and take OUT the shim to get it running and up on concrete. i don't fancy doing this in 3" of muddy backyard water....

lucky so far the oak she's under hasn't shed a limb. can't park it anywhere NEAR the pecan tree... it drops one every week or so.

[Midniteoyl]

A simple breaker bar and socket on the balancer/crank bolt will turn the engine enough to engage a different set of teeth.

[pwf16129]

) Place starter in position and finger tighten the mounting bolts beginning with the top bolt (the top bolt must be mounted first to avoid breakage of this "ear")

2) Check the flywheel's ring gear clearance by inserting the "1/8" gauge tool between the armature shaft and a tooth of the ring gear.

Note: An 1/8" piece of bar stock or 1/8" diameter steel pin can be used as an adhock tool if the GM one is not available. ( It has to be precise to measure correctly, we're not talking a lot of slop here.)


3) If the gauge tool cannot be inserted (fits too tight) use the entire shim or shims across both holes. This moves the starter down and out, Away from the flywheel. Refer to figure 3.


4) Remove shim or shims if the shim tool is loose between the shaft and tooth.

5) If no shims have been used and the fit of the 1/8" gauge tool is too loose, add half shims to the outside pad, only, until the proper fit is obtained. This moves the starter in and Toward the flywheel. Refer to figure 1.
the 1/8 inch is the clearance between the armature shaft and the fly wheel it does work well if the flywheel is in good shape and will save much frustration in shimming .
used this procedure years ago on my 4x4 starter because with the headers is a real pain to work on still using the same flex plate with 260,000 miles plus ,on it .have had several starters but due to heat from headers not chewing up the teeth

[raccoonman]

there is no way to access the harmonic balancer bolt from anywhere under or in front of the rig; there is a heavy crossmember just below the engine and in front of it, and the radiator shroud extends all the way back past the belt area... i tried doing that already! in fact, doing ANYTHING on the front of the engine will require taking the radiator out.... a HUGE undertaking on this rig. just removing and replacing the alternator required crawling under the right front wheelwell and sitting by the wheel.... for a huge MarkV 454 engine, it sure does snuggle down into that frame.....

[raccoonman]

pwf; i'm confused by your "top" and "bottom" bolt designations: my engine has the starter bolted to the block, with the bolts going UP into the block, not back, towards the bell... is "top" the inner, or outer bolt?

i wish this thing had a Kaufmann starter on it.

[Midniteoyl]

Originally Posted by raccoonman

there is no way to access the harmonic balancer bolt from anywhere under or in front of the rig; there is a heavy crossmember just below the engine and in front of it, and the radiator shroud extends all the way back past the belt area... i tried doing that already! in fact, doing ANYTHING on the front of the engine will require taking the radiator out.... a HUGE undertaking on this rig. just removing and replacing the alternator required crawling under the right front wheelwell and sitting by the wheel.... for a huge MarkV 454 engine, it sure does snuggle down into that frame.....

Wow.. really make it easy on you dont they?