[tedmich]

DIY 5sfe crank shaft wrench

I am making a DIY version of the SST crankshaft pulley wrench for my Gen 3 (93) 5sfe with the requirements that its a drill press only project (no TIG welded custom turned "clubs"), super stout and less than $50 using parts from McMaster Carr only.

I had planned on having the 2x 6mm pins as well as the 2x (6mm x 1.0) bolts but decided to go with only the 2 bolts and a beefy 18" tool steel handle that will reach the A arm for bracing.

Will post pictures when done!

 

[tedmich]

Drill press only pulley wrench, from McMaster Carr:
98023A044 $12.12 5/pk
Zinc & Yellow Grade 8 Steel Flat Washer
~48mm ID
~86mm OD,
~4.8mm Thick
(I used all 5 = 23mm ht)

9516K273 $15.35
O1 Tool Steel Tight-Tolerance Flat Stock
1/4" Thick x 3/4" Width, 18” length
(drill through slowly with much cooling oil, as with washers)

Only 1 of 5 (bottom) washer drilled 5mm and tapped
2958A83 $2.10
Metric Black Oxide HSS Jobbers' Drill Bit
5.0mm, 86mm Oal, 42mm Drill Depth, 118 Deg Point
(for 6mm bolt tapped holes)

8305A17 $6.75
Metric High-Speed Steel Hand Tap Taper,
6 X 1mm, D5 Pitch Dia, 4 Flute

2896A25 $2.30
Black Oxide HSS Short-Length Drill Bit
1/4", 2-1/2" L O'all, 1" Drill D, 135 Deg Point
(for 6 x 6mm bolt through holes (4 washers) and 2 x 6mm bolt through holes (1 washer), drill all washers together with 4 bolts securely holding)


Assorted 6mm x 1.0mm cap screws
2 x 35mm length to affix handle to spacer and washer stack
2 x 25mm length to secure other side of washer stack
2 x 40mm to attach tool to pulley (72mm CTC)


total cost of materials $27.47 + shipping
plus fasteners and specific drills and taps about $45

5washers drilled with 4 x 1/4" through holes and used as guide for 4 x 5mm through holes in bottom washer, 5mm holes then tapped to 6mm x 1mm, tap with care to make holes perpendicular to thin washer!

stack secured and then 4 x 1/4" through holes at 72mm CTC drilled slowly through all 4 washers with much oil, handle drilled with 1/4" through holes and all tightened down (6mm pins could be added by drilling from other side)

added bar spacer (14"= 6.35mm) cut from handle to get clearance (see below post)
6mm x 1mm fastener pairs lengths (from top to bottom) 35mm/40mm/30mm

(40mm bolt to pulley gives 17mm thread; plenty!)

2 x 6mm dowel pins (if needed) could be added with 24mm x 6mm pull out dowel pins (97355A302) at $1.31 each
with 6mm hole through 2 bottom washers, and 5mm hole through top 2 washers (plus handle on one) for 4mm x 0.7 bolts to attach threaded dowel pins. You would need two different length 4mm x 0.7bolts: 15mm and 20mm for the one through the handle

careful with handle, its precision ground with SHARP edges, best to chamfer or wrap!

 

[tedmich]

4 washers is too thin! 4.6mm x 4 = 18.4mm , all 5 washers give ht = 23mm!

May still not be tall enough, will report back!

 

[tedmich]

Wrench body needs to be at least 27-29mm high or handle wont clear pulley, 5 washers total = 23mm, so I cut a section of handle (length 1.5") drilled it 2 x 1/4" and used it as 6.35mm spacer between washer stack and handle

fits great with 40mm bolts to pulley, 35mm bolts holding handle to washers and 25mm bolts holding washer stack together (ground extra 2mm down)

and handle reaches A arm no problem

80ft lbs torque on crank shaft bolt DONE!