Old Yella gets a 5th gear!

[Chamba]

The drive shaft is meant to be installed that way. Imagine if your slip yoke slipped out with the rest of the drive shaft connected to the transfer case: it would act like a pole vault, and swing wildly around under there. Not to mention the fact that you would have to do all sorts of fabricating to your transmission cradle to get the non-slip yoked end to fit without rubbing.

Cheers,

Josh

 

[dingbatt]

That's a very good point, Josh, I hadn't thought of it that way. If it slips off with the yoke at the transfer case end then it'll just rest on the tranny support member.... yes, good point.

I flipped that sucker around. In the picture below there is a blue lid from a bic pen for size reference that is sitting in place of the least clearance - I couldn't quite measure it properly but at a guess I'd say its about 15mm minimum clearance. Do you think that'd be enough? I suppose the best way to check would be to get a jack under the chassis at the front somewhere and lift it up until the suspension is at full droop (or the driveshaft hits the support member - whichever comes first)... I may do that this afternoon.



Cheers,

Matt

 

[Chamba]

G'day Matt,

I'd say that is more-than enough. Once you spring it over and install that parabolic spring set with long travel shocks for max articulation you might have to think about adding a CV joint. Doncha love a simple sollution?

Seriously, you have about 3/4" clearance there. I don't know what that would translate to at the other end of the shaft, but I would bet it is about 7 or 8".

Cheers,

Josh

 

[dingbatt]

Yeah I think you're right josh - 15mm of movement that close to the pivot point will translate into maybe 150mm (6") at the front axle at a rough calculation. Should be more than enough.

That said, I am still concerned at about how well the trannsmission is sitting. It seems to me like the whole things is sitting at too much of an angle - so that the output section of the t-case has swung downward. You can see this kind of twisted movement in the tranny support member rubber in post #26. However, the only way this could occur is if the motor has also twisted on its mounts - which it does not look like - or if the clutch housing I used (from an HJ75) is somehow slightly different in its geometry (the flange bolt pattern may be at a slight angle to the tranny bolt pattern) to the clutch housing used on an HJ47 - could this be the case? Anyone know?

The bottom of the transfer case sits 90mm below the bottom of the chassis rails - it looks like too much to me. Especially when compared to that of Kevin's in this post (bottom of #247) Here's a photo of mine:



Or am I just being overly worriesome?

Cheers,

Matt

 

[Awl_TEQ]

Is your transmission cradle perpendicular to the frame centerline? Keep in mind the chassis gets wider as you move back.

Your rear output shaft looks to be roughly at the same height as the bottom of the chassis. Mine is more centered on the chassis vertically. To do this though I will be altering my doghouse to clear the toploader. What exactly hits the underside of the cab when you try and go higher? My transmission and t-case fit nicely through the floor opening and only the rear of the shift tower touches the doghouse.

Sorry - I'll have to recheck your model year and engine to wrap my head around it better...

Edit: Okay - 81 HJ-47. So your floor has only a small access panel and raised seat and tunnel area whereas mine is relatively flat with a full sized doghouse.

 

[herbs]

Yeah the front shaft to crossmember clearance on my bj 42 looks to be almost twice as much as above, but maybe part of that is because of the higher set springs it has? As for the underhang, it does look excessive compared to mine, there's a bit sticking out underneath, but not as much as that. Or maybe it's optical illusion.

 

[dingbatt]

Is your transmission cradle perpendicular to the frame centerline? Keep in mind the chassis gets wider as you move back.

Your rear output shaft looks to be roughly at the same height as the bottom of the chassis. Mine is more centered on the chassis vertically. To do this though I will be altering my doghouse to clear the toploader. What exactly hits the underside of the cab when you try and go higher? My transmission and t-case fit nicely through the floor opening and only the rear of the shift tower touches the doghouse.

Sorry - I'll have to recheck your model year and engine to wrap my head around it better...

Edit: Okay - 81 HJ-47. So your floor has only a small access panel and raised seat and tunnel area whereas mine is relatively flat with a full sized doghouse.

Yep, that's right, a little access panel that goes over the tranny hump. The front area of the toploader of the H55F does not clear the floor properly - but I have already cut out some of the floor to accomodate this. The whole thing could go up higher - maybe 10 - 20mm without hitting any any of the tub.

But I don't think that is the problem - I think its to do with the angle of the drivetrain - tilted to the side slightly so as to allow the output side of the transfer to swing further downwards... if you know what I mean. I used the same tranny support member from my H41 on this transmission - I assumed it wouldn't be any different; the main cast casing of an H41 and that of an H55F is practically the same. And I used the bellhousing from an Hj75 - the one that came attached to the H55F. Could either of these things be my problem?

Would a fresh tranny support cradle rectify this do you think? - the one in there now is 28 years old after all .

Cheers,

Matt

 

[Chamba]

Matt,

Why didn't you use your old bell housing? What condition are your motor mount isolators in? it seems to me that if your driver's side mount was in bad shape, that would make you transfer case tilt that way, no?

Maybe go to the wreckers and see if they have bell housings from 47s and 75s which you can compare. I'd be really suprised if they were different, but stranger things have happened.

If you have room, you can easily lift your cradle, as it sits on top of the L brackets. Try putting some galvanised washers in there and see if you are happy with the result. That may decrease your drive shaft clerance though, as you would increase the angle slightly.

Herbs,

is your BJ42 a 5 speed? Remember that the overdrive unit on the H55 pushes the transfer case back another 2.5" (whatever that is in the French...80mm?), so this would affect the proximity of the drive shaft to the cross member. I am at the office right now, or I would go have a look at mine.

Josh

 

[dingbatt]

Ok, it seems I messed up with my assumptions. It looks like the clutch housing from the HJ75 is different to that off the HJ47. I measured up, looked from different angles, compared the two, and I'm pretty certain that the clutch housing that I have installed with the H55F has a different flange orientation relative to each end than that from the H41. What I mean is that the clutch housing from the HJ75 sets the angle of the transmission differently than that of an Hj47. It looks like the HJ75 clutch housing tilts the transmission slightly to the right by a few degrees, hence dropping the companion flange side of the transfer case closer to the floor... Or so it seems.
The only other thing that I can think of is if the four-hole pattern on the front of the transmission that joins it to the clutch housing is in a slightly different orientation, though I doubt it as I did a bit of research before doing this swap, and hadn't heard anything of this issue before, though every one that I read about had used the existing (H41) bellhousing.

I measured the offset from the bottom rib of the clutch housing to the right hand front bolt that secures the tranny to the cradle.

H41 - roughly 80mm:


H55F - roughly 65mm:



Obviously, the bolt spacing on the bottom of the transmission is the same on both, but relative to the bottom of the bellhousing, the offset is 15mm different.


A quick snap of the offset - note the angle of the rib on the bottom of the clutch housing relative to the bottom of the transmission:



The only thing that I was unsure of before I started this install was if the clutch housing from the 75 would work. Now its come back to bite me on the ass

I could drive it around as is, on the tarmac - no worries, on the trail - I wouldn't want to risk it. I want to do this thing right. So it looks like I'll be pulling the transmission off again, changing out the clutch housings and reinstalling it.

Unless anyone has any other suggestions ..............













please!

 

[Chamba]

The good news is that you won't have to take the pressure plate off, so the whole thing should slide right back together again....I feel your pain Matt. Nothing worse than re-doing a job once it's finished.

I'm with you though- do it now and get it over with. You know that if you drive it around like this, you will just keep putting it off.

Cheers,

Josh

 

[dingbatt]

Hey man, I'm only going to get better at changing out transmissions .

Moral of the story - use an HJ47 clutch housing in an HJ47. I just hope others will learn from my mistake!

Cheers,

Matt

 

[Awl_TEQ]

Look at the bright side - at least you have recent experience to make it go faster


Edit: Ha - I didn't see post 51 before I wrote that - you have seen the silver lining already!

 

[herbs]

Herbs,

is your BJ42 a 5 speed? Remember that the overdrive unit on the H55 pushes the transfer case back another 2.5" (whatever that is in the French...80mm?), so this would affect the proximity of the drive shaft to the cross member. I am at the office right now, or I would go have a look at mine.

Yeah a factory 5 speed is what's in my bj 42

 

[Chamba]

Yeah a factory 5 speed is what's in my bj 42

Mine too, and you are right- the clearance on mine is about 2.5" - about thrice what Matt's is. At least now we know why.

Cheers,

Josh

 

[dingbatt]

I remember now why i used the HJ75's bellhousing - that one had the tacho sender port already drilled into the side of it. my HJ47 has no tacho, no tacho sender, and no port in the housing to screw one into.

That's ok, though, after a bit of a ring around I have located an M20 x 1.5mm tap to thread a hole I will drill into the housing for the tacho sender.

Monday is a public holiday here in WA, so I'll probably replace this housing over the long weekend.

Cheers,

Matt

 

[dingbatt]

done!

I was up till 11:30 last night swapping clutch housings - I had to get it done this weekend to get Old Yella out of my work's workshop!
The transmission is sitting a LOT better now, nice and straight, plenty of room for the front driveshaft past the support member.


pheewwww...........


I'll post some pics later.


It was so damn good driving home last night - 100km/h on the highway with a big old grin on my face the whole way. Its noisy as hell right now without a transmission cover plate on!

The next step along is to fabricate a new tranny cover plate and bend the transfer lever, then I'll fix the rust on the floor pans and reinsulate them and the firewall... any suggestions as to what product to use for insulation? And what's the best way of stripping that gooey bitumen crap off? That stuff is hideous!

Thanks heaps for all the help and support along the way guys.

Cheers,

Matt

 

[Chamba]

Good work, congrats! Bet you wish you had that 5 speed when you drove to Tassie!

I find that that bitumin crap comes off best when it is cold (which may be a problem for you in Perth for the next six months or so).

When the car has not been run overnight, and the ambient temp is about 7 C or so, I find that a flat screw driver and a hammer work really well to get it off. Just get under the edge with the point of the screw driver and tap the handle with the hammer. The bitumin will come off in pieces which range from a 5 cent piece to a compact disc.

So, have you fixed that dent on the driver's side?

Cheers,

Josh

 

[dingbatt]

Good work, congrats! Bet you wish you had that 5 speed when you drove to Tassie!

I find that that bitumin crap comes off best when it is cold (which may be a problem for you in Perth for the next six months or so).

When the car has not been run overnight, and the ambient temp is about 7 C or so, I find that a flat screw driver and a hammer work really well to get it off. Just get under the edge with the point of the screw driver and tap the handle with the hammer. The bitumin will come off in pieces which range from a 5 cent piece to a compact disc.

So, have you fixed that dent on the driver's side?

Cheers,

Josh

Thanks Josh!

Yeah that 5 speed would have been great on the big road trip. It's OK, though, as I plan on an even bigger adventure in the near future - Cape York via the Top End perhaps .....

I'll try to get working on that bitumen stuff over the next few nights then, while its still cold at night - this will give me an incentive to get it done sooner rather than later.

The dent on the drivers' side ........ no, not yet. I tried popping it out with no luck. I even bought a panel beating dolly kit for the job. Its really solid - I suppose due to the curve of the panel . I've never done bodywork / panel beating before in my life, so I'm very hesitant to start hammering away mightily - I also don't know how I'll go popping the window back in place. In all honesty, I find the whole thing a bit daunting. I might just have to pay the money and get a panel beater to sort it out. In the mean time I've sprayed the area with fish oil and poured the stuff inside the panel to help prevent it rusting out. I'd prefer to begin to learn the art of bodywork on something that's in a lot less conspicuous area so that my mistake is not on display for all to see - that is, my floorpans!

Cheers,

Matt

 

[herbs]

Hehe,I'll swap your daunting panelwork for the sheetmetal replacement that I have to do on my bj 42.....

 

[dingbatt]

Hehe,I'll swap your daunting panelwork for the sheetmetal replacement that I have to do on my bj 42.....

haha! How much needs cutting out?