4spd/Splitcase Floor Clearance Issue in '68 FJ40 (1 Viewer)

[rustyj40]

I just did a test fit on my 1969 FJ40 today using the F engine originally in the truck and an H42 and split transfer case from a 1987 HJ60. I am using the early 2F bell housing as well to take advantage of the rear motor mounts, but I don't seem to have the same issue you are experiencing? I am trying to figure out why. Maybe we can compare notes? I am trying to decide between rebuilding the old F engine or putting in a 2F from a 78 FJ45...which is where the bell housing I am using came from.

Here is a photo of my setup in place.

 

[orangefj45]

I just did a test fit on my 1969 FJ40 today using the F engine originally in the truck and an H42 and split transfer case from a 1987 HJ60. I am using the early 2F bell housing as well to take advantage of the rear motor mounts, but I don't seem to have the same issue you are experiencing? I am trying to figure out why. Maybe we can compare notes? I am trying to decide between rebuilding the old F engine or putting in a 2F from a 78 FJ45...which is where the bell housing I am using came from.

Here is a photo of my setup in place.

View attachment 2296732

Can you take a pic from the rear showing the centerline ( and offset ) of the combo compared to the trans tunnel/body?

Dave's combo looks offset to the driver side and slightly angled ( not uncommon )..

Thanks!!!

 

[rustyj40]

Can you take a pic from the rear showing the centerline ( and offset ) of the combo compared to the trans tunnel/body?

Dave's combo looks offset to the driver side and slightly angled ( not uncommon )..

Thanks!!!

Yep. I have packed it up for the evening (CINCO de MAYO!) but will take photos when I get back on it tomorrow. Even though I do not have a photo I can tell you that the drive shafts are slightly offset and slightly angled. As you know the split case with the H42 transmission is a bit longer than the original 3 speed and transfer case. This is my first time through this "procedure" so I plan on taking some good measurements and photos. My biggest concern is all the weight hanging on back there due to the H42 and split transfer case being cantilevered. As it stands the original cross member does not appear to be impacted.

Dave, I am very interested in providing any information I can in helping to solve your issue.

Look for photos tomorrow. If there are others you need just ask.

 

[rustyj40]

I took a few photos and a few measurements...I even tried to do a little math. I feel mostly confident in the numbers for offset and driveline angle. The angles don't look terrible, but if my math is correct the driveline angle turns out to be about 4.5 deg. The offset left to right is better at about 1.6 deg. I only measured the rear. The output shaft of the split case appears to not drop as far as the old 3 speed case, so this is increasing the angle slightly. I will post the photos and we can discuss. I also can show measurements on the floor pan in relation to the shifter on the split transfer case. Which was your original question.

I used a plumb line to get the reference location in relation to the floor for the two flanges and then did the same using the outside frame rail on the passenger side, the second rivet back just prior to the frame turning up over the rear wheel.

Approximately centerline of rivet at the outside frame rail

Calculations...

- If angle C is 88.4 deg then the offset has to be the difference between 90 deg which would be 100% alignment left to right, and 88.4 deg which is about the 1.6 deg I have come up with. This is an acceptable operating angle for most U-joints, correct?

- If the drive line flange to flange is 22.25 in and the difference in height from the floor is 1.75 in then the angle of departure off the transfer case should be about 4.5 deg. This is not awful but over what I would like. Also, i measured from the bottom of the flanges. The rear springs have shims so the differential is tilted to face slightly towards the transfer case which "helps" but doesn't truly fix the angle.

Rear View

Side View, I used a dowel to simulate drive shaft

Dave, perhaps this isn't the exact information you're looking for but it could be used for a comparison. I plan on going with this set up at this point. I need to do the same measurements for my front drive shaft. I am worried that the front is going to give me more trouble.

Let me know what youre thinking. I am going to post the same information on my build thread.

Regards,

Josh

 

[69LC]

Josh, I don’t think that driveshaft is going to be up to the task. Have any Samurai buddies you could pass it on to?

 

[rustyj40]

I took a few photos and a few measurements...I even tried to do a little math. I feel mostly confident in the numbers for offset and driveline angle. The angles don't look terrible, but if my math is correct the driveline angle turns out to be about 4.5 deg. The offset left to right is better at about 1.6 deg. I only measured the rear. The output shaft of the split case appears to not drop as far as the old 3 speed case, so this is increasing the angle slightly. I will post the photos and we can discuss. I also can show measurements on the floor pan in relation to the shifter on the split transfer case. Which was your original question.

I used a plumb line to get the reference location in relation to the floor for the two flanges and then did the same using the outside frame rail on the passenger side, the second rivet back just prior to the frame turning up over the rear wheel.
View attachment 2297810

Approximately centerline of rivet at the outside frame rail
View attachment 2297824

Calculations...

- If angle C is 88.4 deg then the offset has to be the difference between 90 deg which would be 100% alignment left to right, and 88.4 deg which is about the 1.6 deg I have come up with. This is an acceptable operating angle for most U-joints, correct?

- If the drive line flange to flange is 22.25 in and the difference in height from the floor is 1.75 in then the angle of departure off the transfer case should be about 4.5 deg. This is not awful but over what I would like. Also, i measured from the bottom of the flanges. The rear springs have shims so the differential is tilted to face slightly towards the transfer case which "helps" but doesn't truly fix the angle.
View attachment 2297825

Rear View
View attachment 2297840

Side View, I used a dowel to simulate drive shaft
View attachment 2297844

Dave, perhaps this isn't the exact information you're looking for but it could be used for a comparison. I plan on going with this set up at this point. I need to do the same measurements for my front drive shaft. I am worried that the front is going to give me more trouble.

Let me know what youre thinking. I am going to post the same information on my build thread.

Regards,

Josh

It's later...

I've been thinking about all this and I have a couple comments.

1. My math is correct. The angles I calculated and the trigonometry holds, but I am not sure the results tell me what I need to know.

2. I am going to continue this discussion but I am cautious about hi-jacking the original thread!

Josh

 

[MOTOV8R]

I just did a test fit on my 1969 FJ40 today using the F engine originally in the truck and an H42 and split transfer case from a 1987 HJ60. I am using the early 2F bell housing as well to take advantage of the rear motor mounts, but I don't seem to have the same issue you are experiencing? I am trying to figure out why. Maybe we can compare notes? I am trying to decide between rebuilding the old F engine or putting in a 2F from a 78 FJ45...which is where the bell housing I am using came from.

Here is a photo of my setup in place.

View attachment 2296732

'87 h42 should be the long variety. The tcase may be from an '87 if it has the 38mm idler but that trans doesn't seem to be.

 

[Oakley40]

It's later...

I've been thinking about all this and I have a couple comments.

1. My math is correct. The angles I calculated and the trigonometry holds, but I am not sure the results tell me what I need to know.

2. I am going to continue this discussion but I am cautious about hi-jacking the original thread!

Josh

No issues Josh. Hijack away! I'm going to just cut the rib and trim the floor. I wanted to make sure that before I did all of that, I got an informed opinion on my situation.

Thanks for the info though. Your thoughts might help someone else and it may be best in a related post.

Dave

 

[Living in the Past]

if 1964 is newer then yes.. but otherwise it's an FJ45 cab but i was guessing the tube was the same underneath?

I know the support channel at the back is on top of the floor on the FJ40 untill the 73. Not sure about the fixed top but removeable top 45 pickup the the transmission is shaped close to the 73-78 FJ40 transmission cover. Just a little shorter and not as tall. Didn't notice the tub at the back while why I confused yours as a post 72 FJ40 tub.

The second picture highlights how much taller the four speed cover is than the three speed cover. While not in the US other markets got a four speed in the 73 model which why the tub changed 9/72.

 

[rustyj40]

No issues Josh. Hijack away! I'm going to just cut the rib and trim the floor. I wanted to make sure that before I did all of that, I got an informed opinion on my situation.

Thanks for the info though. Your thoughts might help someone else and it may be best in a related post.

Dave

Thanks for the feedback. I did confirm that I have the "shorty" version of the H42 and transfer case. I just picked it up this past week and misunderstood the truck of origin. The good news is the short version fits better anyway. I look forward to seeing your progress!

Regards,

Josh

 

[4Cruisers]

My biggest concern is all the weight hanging on back there due to the H42 and split transfer case being cantilevered.

That's how they all were from '73 through '80, cantilevered off the bellhousing. The split transfer case with drum parking brake is no longer (and maybe ~1/4" shorter) than the one-piece case. Haven't compared the transfer case weights though, but I imagine they're similar.