Urgent Advice Needed in Real Time; 1HZ to H55F ?? (1 Viewer)

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Apr 25, 2020
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I have a 1992 PZJ75 and so happens is that the gearbox has been modified by an early owner where he’s stuck a Adapter plate between the gearbox and bell housing, I reckon his gearbox was bugged and he found a replacement but it wasn’t the right one so he had to use that gearbox. However I did manage to identify the gearbox and it’s a H55F. The original gearbox that was mated to the 1PZ by Toyota was a R151F.
Recently I bought a donor BJ75, now even this truck has had a fair bit of modifications done to the drivetrain. It had a 1HZ mated to a 4 Speed which I reckon is the H42F. The BJ75 had this drivetrain setup perfectly with no adapter plates or spacers.
So what I’ve done now is
-Removed adapter plate and bell housing from the H55F
-Used the bell housing from the H42F that was mated to the 1Hz no dramas
-bolted above said bell housing to the H55F
-Tried mating the H55F and 1HZ but there seems to be a gap of about 1/2 inches Between the Bellhousing and engine. The input shaft is seated right into the pilot bearing.
I’ve gotten as detailed as possible and I’ll attach pictures once I try it again.
But what could it be? A longer Bellhousing ? A shorter input shaft as the OP had said?
My 75 is sitting in my shop crying ahahah so any help would be appreciated thanks beforehand

ABC8D3F6-59A4-4245-B57B-783C87072893.jpeg


7B3F5F42-BBCE-4E0B-9C18-1C219FFAD7F7.jpeg
 
Joined
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San Diego
Sounds like the wrong bellhousing, they are very specific for trans/engine type. Measure the length of the bellhousing versus the stick out of the input shaft, that should tell you something. I can measure the bellhousing on mine for comparison. Also make sure you are stabbing it in all the way. And what kind of clutch/flywheel are you using?
 
Joined
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Sounds like the wrong bellhousing, they are very specific for trans/engine type. Measure the length of the bellhousing versus the stick out of the input shaft, that should tell you something. I can measure the bellhousing on mine for comparison. Also make sure you are stabbing it in all the way. And what kind of clutch/flywheel are you using?
Meaning to say that the Bellhousing between the 1HZ and H42F fit perfectly as that was a running setup, but if I use the same Bellhousing onto the H55F it’s not possible ? I’m gonna be running a Terrain Tamer HD clutch kit im not certain on the size yet but I’m on the way to check rn.
ill measure the lengths soon but it would help if I could compare with yours thanks 😬
 
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Apr 19, 2018
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Chile
Those diagrams would imply all the bell housings are the same ?
Also those are very detailed thanks


the bell housings that are of 1HZ engine with box h41 and h55 correspond to models in series 70 and of course they are the same.
the bell from pz to r151f is unique
1pz and 1hz rear motor bolt is the same as I understand.

You should also consider that there are h55f boxes with the input shaft there are different splines and length, that depends on which engine (gasser or diesel) and vehicle is matted,
 

orangefj45

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norcal
measure the diameter of the seal surface on both input shafts. Then pull the transmission top cover and count the teeth on both of them.
They may interchange ……..
There are different tooth counts and 2 different input seal and bearing diameters.

With any luck, you'll be able to swap parts.
 
Joined
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Holy crap!

Did anybody look at that input gear closely ...…... it's been "shortened" and a new "pilot stub" ground into it.
Yeah a fair bit of modifications been done one this haha you should see the adapter plate that was in between
 
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An update, I managed to remove the input shafts out of both gearboxes and there’s a difference of about almost an inch.
the removal process was a pain 😩😩, I will drive very carefully and try not to destroy the gearbox cause I’m not fit enough to pull it to pieces again 🤣
I’ll update tomorrow once I put it back together !!
thanks all
 
Joined
Apr 20, 2002
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1,447
the 4 speed transmission looks to have an open bearing which might be the earlier style so you would be unable to move shafts between the two transmissions. Georg is correct, measure the two input bearings.

Original, a B engine H55 cut down with adapter as well to mate to PZ. The HZ input is same spline as B series, but shorter.

Does the H55 input cover have the ears? (search for ear photo on this site w h55).

If so, just get the common 1990-1997 hz input for the old h55.--and throw away the dual mass flywheel in pz if that this is still around.
 
Joined
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the 4 speed transmission looks to have an open bearing which might be the earlier style so you would be unable to move shafts between the two transmissions. Georg is correct, measure the two input bearings.

Original, a B engine H55 cut down with adapter as well to mate to PZ. The HZ input is same spline as B series, but shorter.

Does the H55 input cover have the ears? (search for ear photo on this site w h55).

If so, just get the common 1990-1997 hz input for the old h55.--and throw away the dual mass flywheel in pz if that this is still around.
Correct on that I realized last night that the bearings are different, it seems that both bearings are different ; the external diameter for the H55 is greater by 4-5 mm compared to the H42 however the internal diameter is the same so it’s just the matter of finding the correct bearing and pressing that in.
About the shafts; there’s an inch of difference between them but the tooth count and everything is same.
I did manage to roughly assemble the front half of the box and put on the bell housing to test fit on the Hz using the input shaft from the H42.
Everything fit perfectly!! Here’s a picture
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BF1992DA-2399-41DC-AF05-94DE24320423.jpeg
 

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