Ford 6.9, or 7.3 bellhousing bolt pattern dimensions
Hello to all
I'm in the process of making a 6bt adapt to a zf 5 speed and would like to know if anyone can point me in the direction of a drawing showing the dimensions of the bolt pattern on the rear of the ford diesel. The pattern used in the beginning of the 6.9 idi to the 7.3 power stroke used up into the early 2000-2001 models or when ever they stopped putting in the 7.3 and went with the 6.0. I understand that I can buy one of these at destroked and will if necessary. I just thought I would give this a shot since I have the metalworking tools to do the job. I also need to do this to two vehicles and it would be worth while if I can get the plans together.
The bare minimum machines to make an adapter plate like this are also used to get the dimensions off the parts you're copying.
Dowel pin and starter location is critical.
If you actually need 2 of them give me a call. I make the 5.9 Cummins to 7.3 pattern plates that use the 6.0 PSD starter (no bellhousing cutting). If you were in a position to buy two adapter plates I can do two for a deal that would probably make you reconsider even thinking of doing them yourself.
I have been able to measure all of the locations for the adapter using the milling machine and center guage. I'm close to making a plan but I'm looking for a way to measure the crankshaft position in regards to the dowel alignment pins
The crank center relationship is easiest to measure from a bare ZF transmission case or old 6.9 T19 bellhousing.
There are other ways to do it if you don't have those things, basically you will need to attach the IH adapter to a block and then fix the crankshaft location on the adapter using another part (made by you) that fits the crank flange and bolts to the adapter plate. Or pay a metrology company to give you point data for the parts using their CMM.
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The 6.9 and 7.3 are International engines. There was an adaptor used to mate them to the Ford transmissions used in Ford applications. Find one of these at a junkyard.
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Originally Posted by 69rambler
I had not thought of that one. So, I should turn a piece to fit over the crank then bolt it to the adapter. Once mounted to the adapter I can measure it on the mill.
Thanks for the good idea 69rambler
Machinist is an improvised trade, you can do a lot with a little if you have the mindset for it.
Its been a while but i,m now back on the project I started. I have two motors 7.3 and 6.9 and two bell housing adapter plates. I have taken many dimensions and have recorded different results on both motors. The crank position has a .010 difference in height when referencing it to the dowel pins on each motor. Also the crank shaft is off center .005 on both engines. Id like to make some sense of it before I start drilling. Does anyone know how precise the location of an input shaft has to be on a zf5-42
Last edited by DYNA490K; 04-29-2014 at 02:00 PM.
bearing clearance making your crankshaft measurements off? -Chuck
I pried on the crankshaft with an indicator on it and there was very little movement .001-.0015. The .010 vertical change is what has me puzzled. Can't believe the crankshaft center line is that much different from block to block. I'm amazed that I can find the bolt pattern for just about every motor except for the 7.3 -6.9 diesel. I do have one more engine in a truck and wonder if I should pull the tranny and put the adapter on that also. This plate is turning into a lot of measuring. I hoped they were more consistent. Any input is greatly appreciated.
I have come to the conclusion that the .010 difference in crank height is from not eliminating the backlash during measuring. I have measured the jig i made several more times and the height has been within .002 each time on both blocks. I continue to read a .004 - .005 difference in the crankshafts center location in reference with the dowel pins on both motors. So do I build an adapter off center or do i center my measurments? I cannot seem to find any drawing with the bellhousing bolt pattern dimensions so it leaves me guessing. I believed that the zf s5-42, zf s5-47 was a great tranny to swap behind a cummins so I thought there would have been more guys making these adapters. Do these trannies hold up behind a cummins?
I would expect a .005" off center measurement to indicate the features were intended to on center or there is an error in your setup somewhere. When I RE parts I try to get several good examples and compare the geometry. BH geometry usually has a rhyme/reason to it. Might be polar, might be distance/angle. The origin may not be the crank centerline. Metric dimensions are typically easier to figure out.
I would say the starter model and location is more involved than the BH pattern for your application. There are several companies that make this application and this is the primary difference between them. I would caution to fully mock the starter location and assemble it before cutting a chunk of plate.
I know of a local shop that bought a Destroked 7.3 plate and directly copied it and was selling them for near the same price. I thought it was funny as the starter location on those plates isn't ideal (you have to cut the block) and the shop that made them did it on a 16" Y machine- They had 4 ops to make a two op part.
I figure it takes a fair amount of work to make parts like these to a high standard. If you're going to make instead of buy something already available do it because you can improve it somehow.
If you do a nationwide craigslist search you can find many examples of 7.3 ZF5 plates for sale. There's even a homemade one cut from steel plate that's been for sale for quite some time for cheap. Hope the guy didn't make it on a Bridgeport. What a job that woulda been.
Also, the ZF5's hold up pretty good. I've seen a few with broken bellhousings behind Powerstrokes, they just fatigued, nothing catastrophic happened to them. Haven't heard of any broken bellhousings using them behind 5.9's. The ZF5's are a nice tranny. They hold up well, shift nice and run on cheap ATF. They often have banged up reverse slider teeth. Real bad ones pop out of reverse. The problem isn't in the tranny, it's worn clutch pedal pivot bushings under the dash in pre-97 Fords. The clutch doesn't release completely and the slider gets the piss beat out of everytime it's jammed into reverse.
Last edited by 69rambler; 05-08-2014 at 12:22 AM.
I have one more motor and bell housing adapter plate. I plan to pull the tranny and get some measurements off that too. That will make 3 motors and three adapter plates. I should be able to get a good idea on the dimensions with that. I will try to position a 6.0 starter on the plans after that.