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Crankshaft Rebuild Walkthrough


BansheeDFW
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Assembly Part 2 (Outer Halves)

 

It is now time to install the connecting rods and outer crank webs.

IMG_20110902_191919.jpg

 

I left my wrist pin bearings in the package until its time to install the pistons.

 

IMG_20110902_193213.jpg

 

 

8. Cut a shim of the correct thickness into approx. 1/3rd. This will be used to hold the crank pin in location while you press the outer webs in place. (This should be the same thickness shim you used to press crank pins into the inner webs. Both of mine were .015")

IMG_20110902_235715.jpg

Apply bearing grease to inside of the stator side crank pin to hold the shim in place. Note: Do not get grease on your interference press surfaces!

IMG_20110902_194416.jpg

 

9. Support the stator side inner web using the large cut out in the crank web press plate. Three sides of the web should be supported by the press plate. The right and left sides, and the edge where you placed the shim underneath the crank pin. Note: Make sure the shim stays in place when positioning the crank and plate into the press. This is also where you really need additional cross bars spanning horizontally underneath the crank pin. If it is not supported well it will flex and the shim height will not be accurate!

 

10. Install the thrust washers, main rod bearing, and connecting rod onto the crank pin. The rod should face away from you and prevent contact with anything else.

 

11. Select the appropriate shim and place it on top of the crank pin.

IMG_20110902_195219.jpg

 

My stator side outer web required a .038" shim for correct spacing.

 

IMG_20110902_195025.jpg

 

12. Press the stator side outer web partially onto the crank pin. One to two pumps on a manual press or just enough to firmly capture the web onto the crank pin.

 

13. Using some square 123 blocks or the bottom edge of V blocks placed next to both webs check the web alignment. (Rather than create a complicated fixture for this portion, I just aligned the webs using square blocks. Even with a fixture the crankshaft outer webs will more than likely need some smacking to true them perfectly anyway.)

IMG_20110902_234304.jpg

 

Note the gaps between the webs and blocks.

 

IMG_20110902_234342.jpg

 

 

14. Using brass or lead lightly tap the webs until they are aligned with the blocks.

IMG_20110902_234455.jpg

 

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Both sides should align against the blocks.

 

 

15. Continue to check the alignment as you press the web completely down against the shims.

IMG_20110902_200551.jpg

 

 

16. Verify the web spacing is correct. An average 2.125" is correct (Measurement A in the service manual). Also verify the rod side clearance is within spec.

IMG_20110902_231348.jpg

 

 

17. Press the clutch side outer web on the opposite end using the same process. (steps 8-16)

 

18. After pressing the clutch side web into place, verify that the overall width is correct. An average width of 6.141" is correct. (Measurement B in the service manual )

IMG_20110902_235445.jpg

 

 

The crankshaft is now assembled and ready for truing. (If welding, the outer pins should be done after truing the crank)

 

IMG_20110902_235840.jpg

 

Checking the crankshaft prior to truing revealed approximately .002" of runout on each half.

 

 

My TIG welder is in-op at the moment. I'm shooting to have this crank installed and the engine completed in time for the 2011 Little Sahara event. So I have decided to send the crank to Jim at Passion Racing Engines for the final truing and welding. Once I get it back I will update with checking the crank runout and installing the outer main bearings.

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Thanks! But unfortunately work keeps me busy enough I barely find the time to use all those machines, or my Banshee :(

 

The rod kits are here. So I had a little problem with Parts Depot on ebay. Once notified of the problem they stepped up and overnight shipped me a kit no questions asked! ++++

 

So I will be adding some of the assembly steps this evening.

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Yes that model is from solidworks. For 3D cam I like it the best. I also still use Autocad for 2D and and Mastercam for drawing and machining.

 

That's exactly what I do....mastercam for the machining of 3d parts and lettering. I use autocad for my 2d quick drawings of fixtures. autocad blows for 3d design work. for me its solidworks all the way for 3d. its so nice when you change you part and it automatically changes the dimensions on the print, that's tied to the 3d part.

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That's exactly what I do....mastercam for the machining of 3d parts and lettering. I use autocad for my 2d quick drawings of fixtures. autocad blows for 3d design work. for me its solidworks all the way for 3d. its so nice when you change you part and it automatically changes the dimensions on the print, that's tied to the 3d part.

 

Yeah Solidworks is the only way to go for 3D now. Jeez did you use Pro E or Mechanical Desktop? banghead

 

The walkthrough is pretty much complete enjoy!

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...

 

the rod pins can also be pressed in before the center is done and after they are pressed and center'd they should be welded on a crank like this.. of course stock cranks the pins are part of the webs and can not be replaced, thats what makes an OEM crank not completely rebuildable..

 

also the center main pin should be welded as they will seperate at that point also. then the outers can be welded to help seperation also.

even welding just the outer pins wont make this crank not come apart.. rember where ever the weakest point is is where you will have a problem. i have had a few come through that had seperated all over the place and had just the outers welded.. kinda sucks to tell someone that their new 450 buck "welded crank has seperated and has to go in for disasembly and re weld..

 

i'm fixing a stock crank this weekend i'll snap a few pics of it after welding and throw them up if anyone wants to see?

 

 

nice write up. i really dig the fixtures!

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Yes, In the steps there are notes pointing out if you are welding the crank when certain parts should be welded. In this case all the parts (center & inner and outer crank pins) are being welded after due to my TIG being down. Some stock crank pics would be good to add also.

 

Is this going to get stickied?

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