4-speed-5speed GEARBOX SWAP on BJ42

[sunnyicarus]

Hi. I have a Dec 1981 BJ42, 4-speed (H41 gearbox). I bought a BJ73 vehicle (cheap - rusty) and would like to swap the 5-speed (H55F gearbox - from a May 1985 BJ73) to my BJ42. In principle, I know that this has been done previously. I acknowledge that I will have to remount the gear lever, and shorten the tailshaft around 95-100mm, with some concern as regards remounting hand brake (mine operates on the rear wheels but the cable may get sandwiched between the rear of the transfer case and front of the fuel tank), and possible loss of clearance between rear of transfer case and front of fuel tank. Anybody have any suggestions here?? Interestingly, the 1983/1984 BJ42 had the option of a 5-speed (H55F gearbox with a shortened tailshaft), but I suspect that my H55F gearbox is a later version and MAY be slightly longer? Many thanks. Alex

[hotgemini]

By rights, it ought to be pretty straightforward.

Toyota being toyota if you need to change some parts, chances are something off another model (eg. handbrake cable) will fit.

Whereabouts are you, I'm not sure if we kept it, but I might have a stock BJ42 5speed rear tailshaft somewhere, I know we took the flanges off it, but you could just fit your flanges back on.

And on the flip side, what are you doing with the rest of that BJ73, between my BJ70, my mate's (HZ)BJ73 and my brother's BJ74, there is simply bound to be a dozen little odds and ends (brackets, dash bits, interior trim that I need.

Have you considered stretching the wheelbase on your BJ42? If so, it'd make sense to do it at the same time to save having to get another tailshaft later.

-Adam.

[jessie928]

hi mate

bj42's came with factory fitted 5 speeds so aside from the top plate being wrong it will bolt up without a problem.
if you can find a bj42 5 speed top plate even better ( if i could find 10 0f these i would buy them all hehehe)
Jes

[sunnyicarus]

Hi again. MANY thanks for the two responses to my initial question.
To Adam, thanks for suggesting it should be pretty straightforward - I felt similarly. I live in Adelaide, but that is not a problem. (Freight is actually quite cheap - I use Hunter Express). I am unsure here; can I leave my e-mail address here? OK, it is alexk@picknowl.com.au
My understanding is that around 475mm flange to flange is the correct length for the appropriate tail shaft. I would definitely be interested in a small tail-shaft as they aren't a lot around, even without flanges - I could shorten my existing one, but it would be nice to see/feel/experience a factory shaft (I have several shaft flanges here anyway). As regards internal stuff from the BJ73, ask away Adam. I have stripped it all now and it is in the garage (just beat the rain today). It was a country car, and has the sort of wear and tear that a country car typically features as also some rust. I am a little unclear as regards "Have you considered stretching the wheelbase on your BJ42? If so, it'd make sense to do it at the same time to save having to get another tailshaft later". Might you explain?
To Jes, thanks for your reply, and yes, I kinda figured that getting the top cover to the earlier model H55F gearbox (BJ42/FJ42 from 1982/1983, and probably the same for an HJ 5-speed = although I am guessing here) would be the solution to not have to cut my floor plate, but they are pretty hard to find as well. Not a really big job cutting the floor - I'd rather not, but beggars can't be choosers. Thank you for that little bit of extra reassurance regarding fitting it in. I didn't mention that I will need to change my power-take off because mine operates from the rear and that will foul the middle chassis (welded) cross-member - the later version operates from the front and doesn't have a rear flange emanating from the power take off. Modifying the PTO may be quite difficult. Again to Adam and Jes, many thanks for your kind responses, and I hope to hear from you again here!! Alex

[RAY185]

The reason you need a shorter tailshaft is because the 5 speed is longer (let's say 4"). If you move the rear axle back 4" then you can use your original shaft and only worry about a custom length front shaft. When I did my 60 series 5 speed swap into my FJ40 I fitted 60 rear springs at the same time enabling me to use the factory tailshaft. By moving the rear axle back or the front axle forward you are increasing/stretching the wheelbase.

[hotgemini]

To elaborate on what Ray said, repositioning the rear (and front) axles on 40 series cruisers is a reasonably common modification. The longer wheelbase soothes a few of the foibles of a 90" wheelbase like fore-aft rocking and harshness. The most common option is a 60 series rear spring (big eye, so only suits late model 40s), either in it's original orientation, or with the spring reversed (except for the 2nd 'milwrap' spring). This should give about 2 inches more wheelbase for the former and about 6 for the latter, although we did it on a mate's BJ42 recently and I think it was only about 4.5 inches with the flip, although that was after getting the springs reset 2" higher.

You need a longer handbrake cable (flexible drive agencies), a longer flexible brake hose (any brake shop with a brakequip machine), to flip and reposition the rear spring hanger on the chassis, to either just flip or reposition the shock absorber crossmember.

I'd actually like to package an even longer spring under the rear, but my mate rolled his cruiser (driver error, nothing to do with the springs) so the next 'upgrades' will be repairing the damage.

[sunnyicarus]

Hi again. Thanks to both RAY185 and hotgemini for their responses.

To RAY185, problem is much more to do with ensuring that the longer gearbox (somewhere between 95 and 100mm) will fit in inside the (small) space between the existing transfer case and the welded cross member immediately behind, as also between the transfer case and the leading edge of the existing tank which, upon measurement with the existing 4-speed (H41 gearbox) is around 100mm, so a net movement of the transfer case (same transfer case for both the 4-speeder as also the 5-speeder) rearward by 95mm is getting mighty close. Also, the handbrake looks very much like it will get in the way, although moving this will probably be quite easy (off to the RHS and around the tank) and I already have a longer one from the BJ73 anyway.
This is much more of a problem regarding getting it in, although, from what hotgemini and Jes have indicated, it shouldn't be too difficult (Thanks guys). I could elevate the front end engine mounts a tad pulling the engine forward (or I could mount the engine forward by perhaps 20mm - and do the same for the rear cross member supporting the gearbox), just to clear the tank and the welded cross member. Of course the power take off will have to go (for a later version) because that definitely will hit the welded cross-member, as it is operated from the rear (later model PTO's operate from the front). This is the crux of the problem.

Thanks for the details re 60 series springs RAY185 and the greater elaboration from hotgemini. I was unaware that spring dimensions could vary so much within the range of landcruisers. Clearly, that makes it quite a lot easier to move axles around and reduce a problem such as (say) fore-aft movement (which I am so used to - more than 500,000kms in two such beasts). By comparison, tail shaft modifications are minuscule by proportion.

But then again, the 5-speed BJ42 has a tail shaft that is 475mm in length flange to flange which is 95mm shorter than my existing one, so getting one of these, or shortening mine, is not really a problem - I'd prefer the first option. The problem here is, that moving the rear axle rearward presents a difficulty because I have personally constructed and mounted a second fuel tank (90 litres) immediately behind the (welded) cross member supporting the shocks. It is a tight fit there but it has been in there for 20 years and works well. I have modified the exhaust which sits in line with the existing exhaust outlet pipe, and sits underneath the driver's door and side step. The exhaust has been there for 20 years, and despite the straight-through nature of the muffler, has had some impact on noise (only at high engine speeds), but no impact (so far) on reduced exhaust back pressure and burnt exhaust valves, even after 200,000kms.

So, ultimately, moving the rear axle rearwards is probably not the major issue here, and difficult to undertake given existing modifications. It is far more getting the H55F gearbox from the BJ43 in place, and missing the (welded) cross member immediately behind the transfer case as also the leading edge of the tank; although I am cognisant of Adam and Jes's supportive comments to the effect of suggesting that such a modification would actually fit in. To all three respondents I should say THANK YOU and that that you have further inspired a 57-year old person who was already inspired, and for that, I thank you greatly for your kind responses, and would greatly appreciate further such comments. My thanks. Alex

[RAY185]

No worries bra!

[sunnyicarus]

By coincidence, I bumped into someone who owns a 1983 5-speed factory fitted BJ42. Had a measure underneath. Seems that the dimension of his bell housing/gearbox/transfer case is 765mm in total length. The one I acquired from the BJ73 is 745mm or thereabouts, so pretty much, same in length but definitely no longer. So, I am thinking that it should fit right in. I'll update when I am getting it in place. Thanks for all the assistance to date, as also your patience.

If hotgemini is still after internals from the BJ73 maybe I can assist. Anyway, thanks again for all your help. Now I need to find a power take off for a 5-speed, and maybe even a BJ42 5-speed gearbox top plate and short tail shaft and I'll be in business. Thanks again. Alex

[hj 45]

I'd watch the BJ 73 bellhousing, it could put the gearbox on a different angle and you'll have trouble bolting the removeable crossmember to the bottom of the gearbox. I'd take the bellhousing off the H41 4 speed and bolt it to the front of the 5 speed. I have seen this problem with a HJ 75 bellhousing installed into a HJ 47, old mate had to remove the gearbox again and put on the proper HJ 47 bellhousing.

[sunnyicarus]

Hi HJ 45. Thanks for your response. Makes very interesting reading. OK, I have no problems in this regard, as, clearly, I have both bell-housings. Interestingly, I have measured both bell-housings (under the car - so, slightly less than perfectly) and there appears to be a slight difference in bell-housing dimension from front face to rear face. My original bell-housing (H41 4-speeder) measures 231mm but the BJ 73 appears to be 225mm which may be a problem as regards pulling the input shaft out from the flywheel spigot bearing by around 6mm. I had better watch this.

The bell-housing on the BJ 73 appears to be much more substantial than that on the H41 4-speeder as well, and it has a steel support bracket either side of the housing down low by the level of the sump-to bottom face of the engine, attaching the bell-housing to the BJ 73 engine on either side - these are not present on the BJ 42. I believe that the bell-housing on the BJ 73 (H55F 5-speeder) looks like it is made from aluminium, and that on the BJ 42 (H41 4-speeder) looks as if it is constructed from cast iron. I will need to be sure of this.

Unfortunately, the weather should be clearing here shortly (absolutely rotten here in Adelaide lately) and I will get down and establish this (both my BJ 42 and the BJ 73 haven't had the gearbox/transfer case removed yet).
Again, thanks very much for your suggestion HJ 45. Alex

[skootin]

The bellhousing must match the input shaft length. The problem HJ45 is referring to is the angle of the gearbox mounting holes in the bellhousing toyota decided to lower the transfer to get better driveshaft angle.
You may need to mix n match bits. The finished product will be worth the effort but.

[sunnyicarus]

Hi skootin. Thanks for your e-mail. Clearly, the bell-housing and input shaft need match; that was always the plan. I have a feeling that the (H55F 5-speeder) gearbox input shaft/cluster gear is probably in better condition than my original (H41 4-speeder) equivalent, thus I would lean toward this as being my preferred choice. Inspection when removed should substantiate this. And yes, the BJ 73 bell-housing is cast in aluminium.

Re the point that HJ 45 made re angles, and that you helped to clarify, I am a little confused here. Both my BJ 42 (H41 gearbox) and the later BJ 73 (H55F gearbox) support the rear of the gearbox/transfer case at the base of the gearbox and not on the bell-housing. And both appear to feature four bolts that mount vertically upright into the gearbox.

I note that the angle of the BJ 73 appears to be sharper (ie a greater angle between the longitudinal axis of the gearbox plane and horizontal) than is the case for my BJ 42, but I am unclear as regards how that will impact upon which bell-housing I use. Might you elaborate? Isn't this really only just a design difference between the BJ 42 and BJ 73? In fact, looking at the BJ 73, there appears to be more of an angle at the front universal joint (on the rear tail shaft) than there is on my BJ 42, and, clearly, this shouldn't change as long as I manage to squeeze the gearbox in position and use the same engine mounts? Again, thanks for all the input. Alex

[sunnyicarus]

Hi again. Well, I have managed to get an H55f (5-speed) gearbox/transfer case with the appropriate gearbox lid (to suit a 1981 BJ42 SWB) within Australia this week. My question now is, perhaps, more easily answered.

I have one H55f gearbox/transfer case from a 1985 BJ73, one H55f gearbox from a 1986 HJ60 and, now, one H55f from a 1983 HJ45 with the appropriate gearbox lid to insert into my 1981 BJ42 . So, are there any differences between any of these three gearboxes?? If so, is anybody aware of them? My research doesn't provide me with sufficient information. I have seen a list of ratios in a list somewhere, but cannot find it now that I need it. I have so many references pertaining to Cruisers, but, obviously, not this one. Has the dimension of front or rear bearings changed? Oh yes, all gearboxes feature the split transfer case.

Clearly, the lid from the HJ45 is transferable to either of the three gearboxes, so which should I choose? Many thanks for ANY assistance rendered. Kind regards, Alex

[hulsty]

BJ73 box is the only one that work will beghind a B series motor, they run a specific input shaft

[sunnyicarus]

Hi again. My apologies for not responding earlier. I have been away for nearly a week, unexpectedly. It wasn't my intention but things got away from me. Hi hulsty, and thanks for your reply. Sure, I am aware of this, but my question was more along the lines of, apart from input shaft, are there any differences between these gearboxes eg ratios. I have since found out that there are no differences between such (H55f) boxes, apart from variations in the input shaft. So, I will use the BJ73 H55f box and just swap over the gearbox lid from my (new) 1983 SWB HJ45 H55f box, as this box wasn't a great box (had water in it), but the lid is fine. I am unclear if there are any differences between (split) transfer cases, and am wondering if anybody would know about this?? Thanks again for your comments hulsty. Alex

[skootin]

Early t/fer has a 34mm idler shaft and the later is a 38mm i think the change is in 1985. There is also a change in the gears only number of teeth and the idler is obviously different to suit the larger shaft.

[sunnyicarus]

Hi. Thanks skootin for your response and information. I thought the earlier shaft was of the order of around 4mm smaller than the larger (from memory), although all here are 34mm, even the September 1985 (HJ60) transfer case. I haven't counted the number of teeth in the transfer cases but I will do this. Everything else looks to be identical. One didn't feature a PTO gear present, just an elongated spacer. Bearings all look to be identical. I guess all were made prior to the cut-off in 1985/1986. That's fortunate. Thus I can choose the best case? Clearly you know your transfer cases skootin. Thank you. There doesn't appear to be any significant wear that I can see. In fact all output shaft gear spline wear appears to be very similar, with little wear on the shaft. Any other spots in the transfer case at which location wear could be present? I felt it might be inappropriate to mix and match gears (in the transfer case) due to possible uneven wear in different cases. Rather, pick the entire transfer case to use. Wise move? Many thanks again. Alex

[skootin]

Yeah the change could be 10/85. The most common worn part is the HIGH speed gear on the output shaft and the selector sleeve as 99% of the time your in High range. Check the output shaft to, Also the idler gear wears on the inside were the roller bearings run and the idler shaft itself.
Both the high and low speed gears have a bush in them and they can be worn.

[sunnyicarus]

Hey skootin. MANY THANKS for all your suggestions. Clearly, you must be very experienced with Landcrusiser (split-or more) transfer cases. I was incorrect earlier when I said that the HJ60 was a 1986. Certainly was on the registration disc, but manufactured in Sept. 1985.

I will check out the details of your suggestions skootin. One of the gearboxes/transfer cases had a pretty good fit of High speed gear on the output shaft, but I will inspect them all carefully.

Two of the transfer cases are coming to pieces, (the HJ60 still awaits), but both of these gearbox/transfer case that I have semi-disassembled show no damage to the idler shaft or the roller bearings inside the idler gear; the idler shaft in both are really clean, and (appear to) reveal no marks. One transfer case shows some (minor) wear to the (large) taper roller bearings for the transfer-case output shaft, whereas the other is really "clean". Both the better taper bearings for the output shaft, the better high speed gear and output shaft fit, and even the transfer case that features the power take off gear all come from the one transfer case . That looks like it might be the one to use. Further, this gearbox and transfer case also looked to be in better condition based upon the lower level of deposits lodged on inside walls of gear cover and transfer cases walls.

But interestingly, from this choice of two cases, this gearbox/transfer case had a breather connection between the top-up plugs for the gearbox and the transfer case, and the seal between the two was as hard as rock.
So, should I NOT be looking at this transfer case given that it did appear to be in better condition, but noting that it had the breather pipe attached?

Again, your assistance has been greatly appreciated skootin. Kind regards, Alex

[skootin]

The "breather tube" is there for when the seal went hard and the gearbox started pumping oil into the transfer it's a cheap easy fix instead of replacing the seal. If you decide to refit the hose it wont cause any problems and might save your gearbox in a few years.
You seem to be doing a good job i'm no expert i just pay attention to whats going on and understanding how everything works is half the battle. If you decide to swap output shafts and bearings from 1 t/fer to another keep the bearing cones together and also check the preload on the output shaft there is a shim/shim's under the bearing cone in the rear output seal housing that sets the preload.
Happy to help and when your driving down the road in 5th you will appreciate all the time and effort you put in.