Hello all Firstly if I have not got the right area please let me know. My question is what has been found to improve handling and ride comfort of a parallel spring Chev I beam front suspension? Sorry about the long post, after reading a few other posts I have come to the conclusion that the more information I provide it may assist in respondents understanding what my intent is. A bit of background may help to put things into perspective. I have a 1942 Chev 160" wheelbase truck. I will be putting the cab on a 1940's Chev 126" pickup chassis and want to keep the front I beam suspension. I have little experience with driving I beam suspended cars and trucks on the road and wan't to do this right first time. Before anyone try's to convince me to go IFS it is not going to happen. I remember Dad buying this truck when I was three as an old farm truck. Around the age of 7 I drove this truck at slow speed on the farm picking up hay, carting grain and such. At 15 I left home and now in my 40's Dad sold the farm asked if I wanted the truck as I always liked it. It is now safe in my shed but a 160" truck is not for me. A pickup sized truck that keeps the memories alive but is practical to go to swap meets and use at least once a week for short journeys fits the bill perfectly. The cab is still straight enough with some minor work that it can stay original. I intend to put a later model diff in the rear. I am undecided on the engine. It has a 216 splash oiler. My shortlist at this stage is a 292 Chev, a 261 Chev or a Toyota 2F dressed up to look like a 261 Chev. My intended setup is to keep the Chev 2 ton front I beam dropped 3". I need the extra width due to the truck guards being wider. Put thick walled bushes in it so I can use .921" kingpins and 1 ton 6 stud hubs, drums and spindles. Trucks did not have shocks so I need to incorporate these, please suggest what works best. Is a sway bar beneficial? The chev springs are not parallel and are narrower at the front, is this the best way or should I set the springs up parallel? Mono or leaf pack springs? Any other things I should consider. I have tried to read what I can on I beams but most appears to be around the Ford Transverse spring setup or why I should go to IFS. Thanks Steve
Steve, the trucks did have shocks on the front although they only worked in one direction. Yours may be missing.
First, please fill out your profile for your location. It will help as you post here, some things are location dependent. I understand what you are trying to do, keep the memories and use what you have. Are you going to try to cut down your frame to get to your wheel base or use a factory 1/2 ton frame or build a custom frame? The guards, front fenders, and hood on a big truck are much different than the smaller trucks. They are much longer. The wheel openings are much bigger. As well as being wider. So these parts will not work well with a factory small truck frame. I think your axle is much heavier than a 1/2 ton axle. I think that will cause problems with finding someone that can drop it. The next problem will be adapting any kind of lighter springs to adapt to that axle.
126 wheelbase sounds like a 3/4 ton frame, still would have used the same sheet metal as the 1/2 ton (except the bed) but much different than the larger trucks. I believe that Sid will drop the 3/4 ton axles but do not know if he will/can drop the t wo ton axle, ask him. He may have axles available.
Sounds like you might end up with a weird looking truck. It might help if you post a few pictures of the truck as it is (or when it was still together, if you've taken it apart), as well as some pictures you've found of 41-46 pickups, so we can see what Chevy made them look like, in a smaller version. I like that you've done so much planning, but I'm not convinced it will get you quite what you really want. 261s are kind of hard to find, compared to 235s...have you been looking for an engine? Also if you modify the spring perches on the early 40s truck rear end, you can swap in an open driveline center from a 55-62 truck. But you're still going to have 3.90 gears, most likely. Which is fine for an old pickup with a 235 engine, just don't plan on driving at modern freeway speeds.
Some info about dropped axles....this is the go to guy. https://www.droppedaxles.com/chevy-dropped-axles-0 I was going to suggest a 55-59 axle, as they are wider, but I see now the spring mounts are wider too. Dunno if that will work for you
On the front susp., make sure everything is tight! New king pins/bushings, add either tube shocks or later Armstrong lever shocks that are 50/50 and adjust the steering box, so that it is tight. Also make sure the tie rod/drag link are tight, as they are a ball/cup design that are adjustable to remove any play in them. If necessary, you can also add wedges between the axle and springs to increase the caster.
Thanks for all of the replies. Firstly here is a picture of what I am starting with. I have the Bonnet or Hood but it was removed for transport. The good thing about so many relies is it may trigger a thought that I have not yet had. I will try and respond in some sort of logical order. As for the shock absorbers, if it had them they are long gone. This particular truck was built for the Australian Army. As I understand it the chassis and engine and associated bits come from the states and the cabs and some sheet metal was made in Australia by Holden. It has a Holden badge. The main differences between the US cabs are the windshield does not wind open, it has 1/4 glass in the windows and small vents behind the fenders. I have been told the door openings are similar but not the same. I thought I read years ago that shocks were not specified on these trucks but there is a fair chance I am wrong. Therefore are telescopic the way to go or is there any advantage trying to track down a pair of Armstrong knee action shocks? The chassis I intend to use is a Chev 40's 126" wheelbase. It is sitting in my shed. As I understand it the cabs are identical and I have measured the mounting points and they are the same. The bonnet/hood plus grill and splash guard are the same. I have heard of the pickup fenders being mounted and the bolt up in a similar fashion. I was missing one of the splash guards from inside the fender. I picked up one from a 1/2 ton and it can be mad to fit with a couple of holes moved and a new mounting tab. To prevent this looking out of proportion I will still need something like a 255/70 16 tire. Is there a better way to do the steering such as cross steer and late model ball joint ends plus different steering box or just refurbish the original stuff? Thanks so far Steve
oh, you're down under! might make it even more fun.... A couple internet pics. Looks to me like the fenders might be the same piece of metal, but the big ones were trimmed to fit the larger tires. Maybe you could fill in the missing part to make yours into 1/2-3/4 ton fenders? if you can't find any donors down there, which is likely the case.
nothing wrong with an I beam front end if all components are in good shape,as mentioned above. put it together as is and have some fun
Also here is a picture of the smaller trucks, I don't want to go anywhere near this low. As for engines I have been looking, I have a lead on a 292. I like 6 cylinders. I would like to keep an old style looking 6 that goes well. I am open to suggestions. I would go GMC but have never seen one for sale around where I live. The attraction with the Toyota 2F is it very similar looking to a Chev 6 especialy if painted the same colour, with similar capacity. There is a lot of evidence that suggests the 2F was modeled of the Chev but not the same. They are also plentiful and easy to get spares. The disadvantage is that it is a Toyota engine in a Chev truck. Thanks Steve
Here are some suggestions for beam axle trucks. The basic idea is to rebuild to stock, with a few improvements. Start by taking the springs apart, cleaning out rust and dirt, if there are notches near the end of the leaf smooth them out with a disc grinder. Replace the plastic sliders if it had them or use some nylon or grease. One thing I have done is to put strips of brass window screen between the leaves packed with grease then wrap the springs. Now is the time to consider leaving out a few leaves if you are not going to carry heavy loads. The typical truck is like night and day when carrying a load or empty. Go over the steering mechanism and replace worn parts like king pins, tie rod ends etc. Check the steering box bolts are tight. If the box is loose it may be adjusted, be sure and adjust according to the factory manual and don't just wing it, you can easily ruin the steering box. If it is too far gone you may need to rebuild or replace it. Put on a new set of good quality shock absorbers. Now go and get a front end alignment. Do all these things and you may be surprised how nice your truck rides and handles especially when loaded. There is one more thing you can to to make steering easier and that is have your alignment tech reduce caster to a minimum. If you do this you must install a steering damper to prevent shimmy. They are a common accessory on off road 4 wheel drive trucks and are made by shock absorber companies. Auto parts stores sell them. Don't forget to recondition the back springs and put new shocks on back there too. As for tires stick to stock size (narrow) tires and if you use radials pump them up to 32 pounds for easy steering.
As for the engine the 261 is an excellent choice. It is the ultimate development of the stovebolt six and will bolt in place of your existing engine. If you can't find one in a Chev truck they were also used in Canadian made Pontiacs from 1955 to 1962. Chev sixes from about 1953 have insert bearings, full pressure lubrication and aluminum pistons. The 235 used in Chev cars and trucks up to 1962 will fit your truck. The GMC 270 and 302 is also an excellent engine and will fit your truck. The newer 1963 up six cylinder 230, 250 and 292 Chev engines will also fit but you need the bellhousing that goes with the engine and that bellhousing does not fit all Chev truck transmissions although it fits some from 1942 up. The trans that fits is commonly found in trucks. Also used in cars but not quite as common. If you have to hunt for a trans case, all the guts will interchange with other Chev transmissions.
I bet you can buy a kit to adapt tubular shocks but may not be available down under. If I was going to do such an installation I would start by getting the mountings off a newer truck. The lower mount is typically on the spring plate that the U bolts go through, and the upper ones mount to the frame with bolts. Get the distance between them the same as on the donor truck and you can use the same shocks BUT don't try to reuse old shocks, buy new ones, the best you can afford. They may not be leaking or broken but they just don't work as well anymore once they get some miles on them. Other than that I would not monkey with spring mounting locations etc. Just put it back the way the factory made it but with decent shocks, decent springs etc. It may be worth having a spring shop make new springs calculated to the weight you require.
Are the hubs and wheels on the 160" anything like these? The heavy duty hubs and wheels are sort after by military collectors building LRDG replica trucks. It could have the early version of the 235 engine in it. Front fenders were cut for wheel clearance.
looks like the fenders on those Australian trucks are wider than the American version, to fit wider tires. Interesting.
These are Canadian built "India Pattern" wartime trucks, as apposed to "Canadian Military Pattern" (CMP) trucks. Only the cab on the OPs truck is Aussie built, Holden was just a coachbuilder at that point in time. Bigger GM trucks always had bigger fenders, at least back into the '30's.
I mean, compared to the pic I posted above of the shiny green and black truck. I wonder if those fenders are original?
The LRDG trucks had a lot of special mods. I pulled down a Toyota 2F once as I'd heard that they were an exact copy of a Chevy. Literally nothing interchanges. I did keep the rods and pistons though. Rods are about 7.5" long, 0.990" pin, same big end width as GMC but smaller journal diameter. I was hoping they might work in a stroker GMC. Pin end has a pinch bolt like a Chevy 6, not a full floater like a GMC rod, so they don't look very strong.
Apparently they made these Trucks as they were more suited to desert conditions with the wider wheels. The I beam is the same dimensions as the COE model and School bus and they may have used the COE fenders as a starting point. I considered closing in the fenders to give a smaller truck look but then I would have to paint and the build would take a whole different direction loosing the history. The wheels are the heavy duty split rims with huge drums. That is why I want to adapt the spindles of the smaller model. Gafonnon is correct about the 2F not sharing a single part with the Chev. I am sure more than one person has looked at the two engines an thought I can get the Toyota head on the Chev block. Apparently it is a close fit but not close enough to be able to be done.
The toyota engine is a copy of the Chevy, but not a dimensionally correct copy...it just looks mostly the same, it doesn't fit the same.
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