BTE SFI Flexplate
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BTE SFI Flexplate

BTE SFI Flexplate Kit Contains:
1 Flexplate
1 SFI 29.1 Certification Sticker
Drain plug replacement (1/8” NPT x 5/16” L) (SB & BB Ford ONLY)

Step 1 Clean and inspect all parts (verify that the serial number on the sticker matches the number engraved on the flexplate).

Step 2 Punch out the date on the sticker before applying to the flexplate.

Step 3 Using a rubber mallet or block of wood, tap the flexplate into place onto the flange of the crankshaft. Tap it evenly and flush upwards alongside the crankshaft flange. DO NOT draw the flexplate onto the crank with bolts or impact wrench.

Step 4 After the flexplate has been placed onto the crankshaft, using loc-tite on the flexplate bolts and torque them to OEM specifications. To receive proper torque on the bolts, use flat washers only.

Step 5 Hand turn the crankshaft to verify there is no wobble in the ring gear and to make sure it clears the housing.

NOTES: 1) Welding weights on the flexplate for engine balancing is not recommended and voids warranty; 2) drilling holes for balance is permissible, but not recommended; 3) high perfomance and racing applications new flexplate bolts with a rating of 180,000 PSI or higher are recommended.

Ford SB & BB Stock Torque Converter: remove standard drain plug and replace with special Allen Head drain plug to preclude interference with flywheel. If using a GM Converter, use Crank Adapter BTE 429600.

Starter Alignment and Shimming:

1. Begin the shimming process, if needed, by using a feeler gauge to measure the flexplate to starter clearance with the current setup. If you don’t have a set of feeler gauges, a paper clip can be used as a cheap alternative (they are normally around 0.035” to 0.065” thick). Insert the measuring tool between the flexplate teeth and starter teeth. You are looking for a clearance between 0.035” to 0.065”. If clearance is too close, you will need to add shims to where the starter mounts to the block.

2. If shimming the starter is necessary, be sure that the starter-mounting surface is clean from any excessive gunk or paint. After cleaning, reinstall the starter and recheck the clearance between the starter teeth and flexplate teeth.

3. After cleaning the mounting surface and rechecking the clearance, if the tooth-to-tooth clearance is still not correct, start adding one shim at a time until proper clearance is achieved. Most aftermarket starter shims are 0.015” and increase the tooth-to-tooth clearance to about 0.0075”. Normally using one shim will cure the alignment problem. If more than 4 shims are used, there is a good chance that the mounting surface has been machined down or it is warped. Please refer to your local machine shop for advice on your block.

4. After adding the shim or shims, recheck the clearance in several different locations, preferably 120° apart.

5. One more critical location to check is the clearance between the flexplate ring gear and starter. Normally this is not an issue, but make sure there is a 0.100” clearance with a variance or 1/-0.040”. Again, check it in several locations. If there are clearance issues the flexplate may be warped and you should return it to your dealer. Although we check each flexplate that we manufacture for run out, the flexplate could have been damaged during shipping.

Possible Causes for Damaged Flexplates:
1. Not installing flexplate perpendicular to crankshaft flange.
2. Engine or torque converter out of balance.
3. Worn front pump bushing.
4. Too much end play on the crank from excessive thrust bearing wear.
5. Improper bolt torque and/or not in proper order according to OEM specs.
6. A bad starter can wear or break off the teeth on the ring gear.
7. Not properly shimming the starter, if needed, to align with the starter ring.

Posted by Brandon Barrentine at 7:02 PM