Transmission Rebuild

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This is a work in progress. Check back again soon.

This web page is about restoring/resto-rodding a 1950 Ford F-1 pickup, and is one of a series of articles documenting the project. I am providing this in the hope that it is helpful to fellow Ford truck owners, but beware that there are many ways to accomplish the same goals... I have only shown one way. Also, keep in mind, that my comments are specific to this year, make and model, and should not be generalized. Feel free to drop me a line if you see mistakes or need more information, but please understand if it takes me a while to respond. To go back to the main project page click here.

Our Plan

The transmission was a simple rebuild: no mods. Just new bearings, bushings, seals and syncro's.

What We Started With

The truck had a period-correct floor-shift 3-speed top loader, the light duty version. We're not sure if its the originally tranny, since the we know the engine is not original, but in any case, its the correct type. (In the second picture, the starter is shoved under the rear bearing support to prop up the transmission.)

Tear down

We tore the transmission down in December of 2006 (after we had the engine running and tuned). The first/reverse sliding gear had a couple of nicked teeth, but was probably fine. The only surprise was the cluster gear, which had 3 badly damaged teeth, and the reverse idler gear which had nearly an entire tooth missing.

According to the Ford Truck Service manual, the part number for this cluster gear is 8M-7113, and the intermediate gear is 51A-7102. The case is stamped 78-7006-B, and there is no serial number stamped above the inspection hole (which is period correct as well). The synchro assembly is the "new style" with the shifter fork slot in the rear of the sleeve. The first/low sliding gear appears to be a 21C-7100 based on the 1/16" step cut on the shift fork flange. The tailshaft is stamped 21C-7049-A. The speedometer drive gear is 22 tooth. Click here for some hand notes I made.

Parts List

Here's our parts list. All parts are new, unless otherwise specified. I'll make one additional comment here: in my zeal to start ordering parts, I ordered some parts from NPD beforehand. This was a mistake. Not only was NPD more expensive, but some of the parts were wrong (they were for a side loader). I recommend buying everything you can from VPS. Mac Van Pelt will make sure you get the parts you need. Some of the other items, especially related to the clutch pedal assembly, you'll need to get elsewhere, like C&G.

Description	Supplier P/N (Ford P/N*) {Qty}	Cost**	Supplier
TRANSMISSION - INTERNAL
GEAR, CLUSTER	68-7113-A (28 TOOTH, HELICAL)	295.00	VPS
GEAR, FIRST/REVERSE SLIDER	68-7100-B (29 TOOTH, HELICAL) [USED]	45.00	VPS
GEAR, REVERSE IDLER	68-7141 (18 TOOTH, HELICAL)	65.00	VPS
THRUST WASHER, CLUSTER GEAR FRONT	B-7119	6.00	VPS
THRUST WASHER, CLUSTER GEAR, REAR	68-7129-B	15.00	VPS
BEARING, INPUT SHAFT	F-7025-1	44.95	NPD
BEARING, OUTPUT SHAFT	F-7065-1	34.95	NPD
OIL SEAL, OUTPUT SHAFT	21C-7052 (NATIONAL 470059)	5.50	VPS
OIL SEAL, INPUT SHAFT	78-7052	5.50	VPS
BUSHING, CLUTCH EQUILIZER PIVOT	40-7508 {2 REQD}	6.00	VPS
KIT, GASKETS	B-7153-F	13.00	VPS
BEARING, CLUSTER & INPUT (SHORT)	B-7118 {2 REQD}	14.00	VPS
BEARING, CLUSTER (LONG)	B-7121	7.00	VPS
SYNCHRO REPAIR KIT (INSERTS & RINGS)	51A-7109S	10.00	VPS
SYNCHRO BRASS RING	81A-7107 {2 REQD}	14.00	VPS
SHIFTER
LEATHER SEAL, SHIFTER LEVER, TOP LOADER	B-7248	2.00	VPS
PIN, GEAR SHIFT LEVER (FLOOR SHIFT)	B-7221	1.00	C&G
SPRING, GEAR SHIFT LEVER	B-7227	1.50	C&G
KIT, GROMMET, GEAR SHIFT LEVER	01A-7354-K	20.00	C&G
CLUTCH & EQUALIZER ASSY
DISC, CLUTCH	ASK DAD	X.XX	?
BEARING, THROW OUT	ASK DAD	X.XX	?
BEARING, PILOT	ASK DAD	X.XX	?
PLATE, PRESSURE	ASK DAD	X.XX	?
SHAFT, BALL AND BRACKET, EQUALIZER	F-7507-1 (FORD 01Y-7507)	19.95	NPD
PIN, CLUTCH FORK TO SHAFT	352580-S	0.90	NPD
SPRING, CLUTCH PEDAL RETURN	F-7523-1 (FORD 7RT-7523)	4.25	NPD
BUSHING, CLUTCH PEDAL TO IDLER	F-7526-1 (FORD B-7526) {2 REQD}	11.50	NPD
SPRING, CLUTCH RELEASE FORK	48-7562	1.75	C&G
SPRING, CLUTCH EQUALIZER	01A-7545	1.75	C&G
WASHER, CLUTCH EQUALIZER BRACKET (RUBBER)	01A-7539	.50	C&G
CLEVIS, CLUTCH ROD	B-7532	10.00	C&G
PAD, CLUTCH PEDAL	11A-2454	6.00	C&G
SEAL, CLUTCH PEDAL	B-35184	3.50	C&G
BUMPER, CLUTCH PEDAL ARM	7C-2473	3.00	C&G
MISCELLANEOUS
KNOB, GEAR SHIFT, FLOOR SHIFT	F-7213-1 (FORD 91C-7213)	6.00	NPD
KNOB, GEAR SHIFT, FLOOR SHIFT, V8 LOGO	78-7213-C	12.00	C&G
MOUNT, TRANSMISSION	21A-6068	28.00	C&G
SEAL, TRANSMISSION COVER TO FLOOR PAN	7C-8112125-S	17.50	C&G
PAINT, ENGINE ENAMEL, FORD BLUE	DE1601	4.00	LOCAL
PAINT, ENGINE ENAMEL, FORD RED	DE1605	4.00	LOCAL
BOOT, FLOOR SHIFT LEVER	F-7242-1 (FORD 99A-7242-B)	24.95	NPD
TOTAL		758.95+

* The Ford P/N is supplied in () if different from the supplier's P/N.
** Approximate (USD, net totals; does not include taxes or shipping).

Suppliers

NPD - National Parts Depot; Ocala, Florida, 800-874-7595
C&G - C&G Early Ford Parts; Escondido, CA, 800-266-0470
VPS - VanPelt Sales, Batavia; OH 45103, 800-299-7496

The Rebuild

First, get Van Pelt's book listed in the Reference section. The Ford top-loader went through several design changes over the years, but there are a bewildering number of interchange possibilities, given the correct gears and thrust washers. This book will help a lot.

Since we needed to replace the cluster gear, we decided we wanted to put in a Lincoln Zephyr (L-Z) gear set, which requires changing the cluster, main drive, and intermediate gears. L-Z gears provide a taller 1st and 2nd gear, and with the extra power available to us (see the Engine rebuild), having a "granny" first gear was not needed. However, our plans were thwarted because the gear manufacturer had shut down the line making these gears to re-tool (as of March 2007). Because we did not want to wait, we ended up abandoning the plan to use L-Z gears.

You may notice above that I mentioned the transmission originally had a 8M-7113 cluster gear, but the parts list shows a 68-7113-A cluster gear. As of March 2007, there is a shortage of gears for top-loaders, so we had to use what was available. The 68-7113-A cluster gear is nearly identical to the 8M-7113, the only difference being you need to use different thrust washers (see the parts list).

Painting

We used high-temperature ceramic engine enamel, Ford Blue (Duplicolor DE1601), for all the internal painted surfaces, and Ford Red (Duplicolor DE1605) for the exterior. Be sure to do a good job of masking.

Transmission Assembly

We followed Mac Van Pelt's book to reassemble the transmission (see the References). Van Pelt guides you through reassembly using a 1940 closed-drive transmission as an example, which is different than our later model open-drive top loader, but he does a good job of covering the other transmission combinations.

There were still a couple of points of confusion for us:

The 7080 rear oil baffle. The 1948-50 transmission oil baffle is very small, and can hardly be called a baffle at all. Its more like a spacer. We initially mistook the 7040 front oil baffle for it, but that cannot work because you can't get the mainshaft into the case with it on the rear (the baffle won't clear rear bearing opening).
The 7071 Washer. Our transmission didn't have one (or at least we could not find it, and we didn't remember ever removing this part). After studying diagrams of the later transmission styles we were confident that the our tranny did not use this washer, and after installing the intermediate gear and synchronizer, we were further convinced because there was not enough room for a washer in any case. The lash measurement was right on the money (.004").
Two of the three synchronizer inserts (7116) didn't fit in the hub. These inserts are stamped steel, and all we had to do was remove a little material at the 4 corners to get them to fit. These inserts are very hard and not easy to file, so we used a die grinder.
The replacement low/reverse sliding gear had a smaller flange than the original. We called Mac Van Pelt and he said the replacement gear was an earlier style, but they were interchangeable. (See pictures, the original gear is on the right.)

Cluster gear sitting in case bottom (countershaft not installed).

Shifter Rebuild

Waiting for parts

Hits & Misses

TBD

Things that worked great

Things that didn't work so great

Unexpected things we learned

Time Line

December 2006 - teardown, cleaning, painting
Spring 2007 - parts research, ordering
March 2007 - transmission assembly complete
December 2007 - built wood stand for transmission
May 2008? - shifter assembly complete.

Last Updated: Monday May 30, 2011