Topic: Ancient W56 problems?

[cgbemis]

I just picked up a W56 for my 2x-4x conversion, and it is the early model w56 with the aluminum center plate as apposed to the cast style. According to the tranny section, this is the only model of w56 that toyota made with the Aluminum piece, then in 86 they were all cast. My question is this. Should I replace the aluminum piece with a cast one? Has Marlin had serious issues with these older style aluminum sections hogging out? Would a center section from another style of w56 fit, or is the aluminum one of a specific design? Finally, if I was to replace this center plate with one from another w56, which one would be best, (IE, are there w56's with larger bearings than the one I have)? As always, thanks for your help.

[BigMike]

Hey cgbemis,

it is the early model w56 with the aluminum center plate as apposed to the cast style.

This is a 1985 model W56. Nice grab

Should I replace the aluminum piece with a cast one? Has Marlin had serious issues with these older style aluminum sections hogging out?

No, this is not necessary at all. In fact when I rebuild my W56, I will swap out the cast iron center section for an aluminium one to save weight. I once asked Marlin about any strength concerns and he said he has never seen an aluminum center section wear out. However, the '85 W56 also features aluminum shifting forks. And while these are nice to look at, lighter, and a stronger material than steel, they wear out faster than the steel forks with brass finger pads. This almost seems crazy, how can aluminium wear out faster than a soft metal like brass? Well its because of the properties of "like metals." Steel on steel will last longer than Aluminum on Steel. And Brass on Steel will out last Aluminum on Steel.

But I wouldnt be so worried about your aluminum forks. Yes we see them worn out on tear downs, but they still last well over 150+ miles. But knowing that your tranny is used, replace your shift handle nylon socket and then check to see if there is excessive play between gears.

Would a center section from another style of w56 fit, or is the aluminum one of a specific design?

Yes, they are completely interchangeable.

Finally, if I was to replace this center plate with one from another w56, which one would be best, (IE, are there w56's with larger bearings than the one I have)?

Nope, they all use the same bearing ID and OD through all of 1985-1995, both early and late models. When Marlin rebuilds a HD W56 he has out sourced same ID and OD upgraded bearings with much more static and dynamic ratings.

Regards,
BigMike

[cgbemis [OP]]

Glad to hear I don't have any problems with the aluminum as apposed to the cast. The tranny is used, and given the age I will probably go ahead and replace the shift forks as they are probably fairly worn. Just so I understand you correctly, when Marlin does the HD upgrade, your saying he uses a bearing that are the same inner and outer diameter as the stock bearings, but is upgraded (has more ball bearings) correct? I want to make sure, because I will probably be ordering one of these kits from Marlin if the tranny innards are in fact 20 years old, and in need of replacing.

Also just as a side note, what is the deal with these tranny's that have the aluminum center section? My friends and I have pulled several W56's out of 85 vehicles, and as far as we can tell, this is the first one we've ever seen. Where these only produced in limited numbers? Where there several factories making these trannies, but one decided to go with aluminum as apposed to cast? What's the deal?

[BigMike]

Just so I understand you correctly, when Marlin does the HD upgrade, your saying he uses a bearing that are the same inner and outer diameter as the stock bearings, but is upgraded (has more ball bearings) correct?

This is correct, however I dont know about the bearing count, possibly its better heat treated metal or the race is wider, I dont know for sure, but yes same id and od, just stronger.

I want to make sure, because I will probably be ordering one of these kits from Marlin if the tranny innards are in fact 20 years old, and in need of replacing.

This is a good idea, but I am not sure if Marlin offers any kits featuring the HD parts, I think the HD option is only available as a full rebuild. You would need to call in and ask to find out for sure.

Also just as a side note, what is the deal with these tranny's that have the aluminum center section? My friends and I have pulled several W56's out of 85 vehicles, and as far as we can tell, this is the first one we've ever seen. Where these only produced in limited numbers? Where there several factories making these trannys, but one decided to go with aluminum as apposed to cast? What's the deal?

Well to my understanding ALL 11/84 - 11/85 EFI 4WD 5-speed trucks came with W56's featuring the aluminum center section. You might want to check with the transmissions that you removed to verify that they were not the original tranny by the transmission code stamped on the tranny. The first two numbers are the month, next the year, and then the serial number of the trans. For example, 06502456 would be a June of 85 and the 2,456th trans built in that month. I'm willing to bet that the cast iron W56 trans you removed from your 85 vehicles were not OEM, but replaced from some 86-95 model truck.

My only guess as to why Toyota used the aluminum is that it was the first debut year for the W56 and Toyota wanted it nice and flashy. Maybe the first EFI prototype show trucks used aluminum in their first prototype W56 trans..

BigMike