I’m having problems mating my zf with my engine. I’ve never had and engine/trans so hard to mate up. I have a zf-2 with a safir bell housing with McLeod dual clutch package. I spoke to Bob Wood before ordering and gave him all the proper information for my zf. I set the distance for the throw out bearing. The best I can get it is about 1/4” away!! I be pulled it numerous time to check and recheck. Input shaft has plenty of depth to go so it’s not bottoming out. I assumed the input shaft and pilot bushing were slightly off so I aligned the the trans and engine with a digital level so they would be exactly level and used studs on the bellhousing to get the exact proper height and still can’t sink it in the last 1/4”. I can put the clutch lever on and still get some wiggle so it’s not hitting the clutch fingers yet. Any thoughts????
Help mating zf and dart block!!
- Thread starter Pmccooey
- Start date
Per Bob, the T/O bearing needs to have all the shims taken out of it (3) but you say that is not the binding point. The ZF "should" have a 17mm pilot on the input shaft end which needs to be inserted into the Ball bearing pilot which is in your crank. Did you try the bearing on the ZF shaft to make sure it fit? Is the pilot bottomed out in the crank? I have yet to do what you are doing but have talked to Bob about it and measured all my parts several times.
David Garton
Supporter
I seated mine in the crank and with it flush the trans would not have seated. I would grease the pilot shaft and slide the trans back in until it stops and pull the trans back out inspecting the grease on the pilot shaft and see if the grease is wiped all the way to the splines of the input shaft. If it is the pilot bearing needs seated into the crank.
Sometimes things go wrong just because we do not look at the right place. After checking as David described, maybe you could try to remove the clutch mechanism and disk, because it is allaways difficult to allign everything, and try to put the gear box back in place. It shall go freely, if not the problem is coming from the bearing, by the way do you use a bearing or a bronze bushing ? the second solution is easier to assemble and more reliable.
Also, you do have the backplate on the engine block, correct?
Julian
Lifetime Supporter
Have you tried individual combinations? I'd mate up the bell housing alone and check it clears the clutch, then remove the clutch and see if the ZF and bell housing mate up. Are you able to get the bell housing on the alignment dowels? Sometimes the engine and transaxle will require indexing and offset dowels are available.
Pat, something that has me wondering is this statement.
“I tried the bushing on the zf shaft when I got it and it ‘fit’ (just started it as I didn’t want to have to pull or press it off”.
The pilot bearing should never be a tight enough fit where you are concerned about pressing it on or pulling it off. And the inside diameter gets smaller when you press it in the crank. Add this to any tolerance stack up from parts from separate suppliers and you could easily have the situation you are explaining. Pull the transaxle and carefully inspect the pilot bearing for any sign of bind. You could also put some blue (or any color) layout dye on the input shat and reinstall the transaxle. Pull it back out and look for missing dye on the shaft. These transaxles are way to expensive to be drawing them together with bolts and risking damage.
Just my thoughts.
Regards Brian
“I tried the bushing on the zf shaft when I got it and it ‘fit’ (just started it as I didn’t want to have to pull or press it off”.
The pilot bearing should never be a tight enough fit where you are concerned about pressing it on or pulling it off. And the inside diameter gets smaller when you press it in the crank. Add this to any tolerance stack up from parts from separate suppliers and you could easily have the situation you are explaining. Pull the transaxle and carefully inspect the pilot bearing for any sign of bind. You could also put some blue (or any color) layout dye on the input shat and reinstall the transaxle. Pull it back out and look for missing dye on the shaft. These transaxles are way to expensive to be drawing them together with bolts and risking damage.
Just my thoughts.
Regards Brian
That could actually be the problem. It would explain the 1/4”. I’ll pull it apart and let you know.
The tolerances are very close on the bushing. Even when I’ve had to pull it apart it’s really in there where I need a pry bar to separate the engine and trans axle. I tried some scotch brite in the input shaft thinking it might have some residue on it or something but it’s clean.
Yes I have the backplate in.
Bill Kearley
Supporter
Re post 11, I think you found your problem !
Okay I pulled everything apart again. I pulled the pilot bearing (been so long I thought it was a bushing in there!). The bearing is Koyo 6003RS. It is spec’d at 17mm ID. The input shaft on the ZF is a;so 17mm (actually measurements I got on it were anywhere from 16.93 - 17mm. I contacted Safir to make sure this is the proper bearing but have not heard back from them yet. Before pulling it I tried to see how much more it could go into the crank. While it could go in more I’m not sure if it was the full 1/4” but it looked about right eyeballing it. Before I order a new bearing (just because since I pulled it out anyway) does anyone know if this is the correct bearing for a ZF-2 coarse spline into a 302 block (block is a Dart 302 stroked out to 363)? I want to make sure that not only is the ID and OD correct but also the thickness of the bearing itself. Thanks all!!
I have the same bearing from Bob Wood. It is 17mm i.d. The ZF snout is 0.669" (16.993). The snout has to actually interfere with the bearing. It is not "loose". I would take emory cloth and polish your input shaft some. I can't comment on your crank and whether it is different from a standard 302 crank. The bearing must be seated into the crank all the way.
Thanks! Ordered a new Timken bearing and will replace it. I’m not sure why others on here are stating it should easily slide on and off? My mistake was not seating it all the way into the crank.
Pat, I was going by this statement in your initial post “I assumed the input shaft and pilot bushing were slightly off so”.
A bushing is a slip fit and usually a bearing has a interference fit on the shaft and a press fit on the crank. Everyone is trying to offer ideas and from there hopefully a resolution results. It looks like you may have found your issue. Best of luck with the final fitting.
Regards Brian
A bushing is a slip fit and usually a bearing has a interference fit on the shaft and a press fit on the crank. Everyone is trying to offer ideas and from there hopefully a resolution results. It looks like you may have found your issue. Best of luck with the final fitting.
Regards Brian
Ian Anderson
Lifetime Supporter
I have never owned a ZF but read on this site daily.
There are some ZF boxes with a slightly longer input shaft….they were made for BMW M1 cars.
If you happen to have this type of box or input shaft it may be bottoming out in the crankshaft.
There is actually a thread on here somewhere a thread about this and the car being driven and damaging the box and crank shaft.
Could this be the cause of your interference?
Ian
There are some ZF boxes with a slightly longer input shaft….they were made for BMW M1 cars.
If you happen to have this type of box or input shaft it may be bottoming out in the crankshaft.
There is actually a thread on here somewhere a thread about this and the car being driven and damaging the box and crank shaft.
Could this be the cause of your interference?
Ian
