L48 starter - shims or no shims?

[The73vetteman]

Just went to fit a new starter in my '73 L48. Got it secured with two new bolts into the block, but the new brace I bought wont fit. The bolt holes wont quite align unless I was to lower the starter by 1/16th or so.

There was no brace on the starter I removed, nor were there any shims.

So, should there be shims between the bottom of the block and the starter?

If yes, how do I work out what thickness I need, or do I just guess?

Thanks in advance,

'73

 

[JohnZ]

Some starters need a shim or two, some don't; with the starter bolted up and the Bendix extended so it's engaging the ring gear, you should be able to insert the end of a paper clip (about .030") between the tip of a drive pinion gear and the root between the two teeth on the ring gear (on an automatic where you can get to it with the converter cover off). Just bolt it up without shims and see how it sounds - if it's noisy (metallic ringing sound), add a shim and try it again.

You definitely need the starter brace to carry the weight of the front of the starter; without it, you stand a good chance of breaking the starter nose - it wasn't designed to carry a cantilevered load like that. Most "Bubbas" leave it off ("hey, man, it ain't my car, and it's a PITA to install it"). You may need to slot one of the holes a bit - the top bolt is a 5/16"-18 x 1/2"; any longer, and it'll bottom out in the block before it's tight.

 

[drags1998]

To the best of my knoledge,NO SHIMS!!!! But before you make that decision,Bolt it up with the 2 bolts & try it. If its not noisy(grinding or abnormaly loud) It does not need shims!!!!! Ajust the new bracket!!!!!! NOT THE STARTER!!!!!:L

 

[JohnZ]

SB Chevys have used starter shims (at the factory) on an as-needed basis since 1963, when the starter attachment changed from the bellhousing to the bottom of the block. The brace is there only for long-term durability of the starter nose, not to change pinion/ring gear clearance.

 

[The73vetteman]

Thanks for the advice guys. One further question John. You said:

"with the starter bolted up and the Bendix extended so it's engaging the ring gear,"

Is there an easy way to extend the Bendix?

'73

 

[AKRAY4PLAY]

12 volts

 

[76okievette]

Hello, I just finished starting my car after a starter replacement, 1976 L-48, just bolted the starter up no shims needed, use the support get the starter bolted up and go enjoy. My only problem was the strarter just fits between the exhust pipe and the block, there are a couple of metal lines running down the oil pan, don't mess with those when you are trying to get the starter out. The new took a little wiggling but it slid right in.

 

[blasterfdc]

I just changed mine and it is noisy, not a grinding noise just really noisy. I tries shimming it and that made the gap larger. Is it possible the mount pad on the starter needs machined down a little???

 

[theo]

GM Service manual says that to REDUCE the lash, you just shim under one bolt of the starter. Seems initially daft that adding shims will reduce the gap, but I guess if you think about it, this tends to swing the starter inwards, if you shim the outboard bolt. I must admit I haven't actually done this myself, so perhaps others would like to chime in...
That procedure was from the 80 GM vette manual, I imagine this would apply to all small block vettes at least???

 

[Cream79L82]

Your starter manual is right. There is an inside and an outside bolt to mount the starter. If you break a shim in half and put in on the outside bolt (the bolt furthest from the flexplate/flywheel) and torque her down... the starter is not able to flatten all the way up to the block. Thiseffectively 'rolls' the mounting point of the bendix in/towards the flywheel.

If you need to get closer, just putting in more shims won't help you if you are putting in whole shims. Only use halves and only on the outside. I know this, sadly, from too much experience. I've been through probably 5 starters in less than two years and I've finally got about the right gap with 5 shims on the outside bolt. Good Luck.

-jon