You can use the flat seal on a Corvette.
For a clue as to why, Miatas and RX-7s used the same trans. The Miatas and FCs, with IRS, used a flat seal. SA/FB, with a solid axle that plunges the driveshaft in and out as the suspension moves, have a seal with the cone.
I think it's just a wiper to keep the plunging from pumping crud into the seal.
In reply to Pete. (l33t FS) :
That's good. I didn't think there was a problem swapping seal styles, but wanted to be sure. Interestingly enough, both the Impala SS and the 92 S10 used flat seals despite being solid rear axle. The 2000 S10 is the only one that used a cone seal.
Minor note so I remember. I may need an adapter u-joint to install the S10 yoke on the Vette driveshaft. I think the bearing cap size and the overall width of the u-joints is different. Width might be solved once I remove the u-joint from the yoke and see if it is already machined for snap rings. I'll edit this post when I know.
EDIT: Not sure about the width, that may just be the nature of different styles, but the caps on the S10 yoke are 1-1/8", and 1-1/16" on the Vette driveshaft. Yoke does have grooves but they are so far in there's no way they'd work for snap rings.
Today's tech tip: When removing u-joints, check to see if the original plastic filled ones had been replaced with joints with inner snap rings before getting out the torch. That was a bit of a waste of time.
I'm going to start looking for an adapter u-joint. May be interesting. I need one side with 1-1/8" caps and provisions for inner snap rings and another with 1-1/16" caps and provisions for outside snap rings. Found something on eBay, but it doesn't show which side has which snap rings. Also, should have coated caps, to keep galvanic corrosion at bay. Anyone know of a site that shows diagrams? EDIT: Looks like I need a 3R to 1310, which is fairly easy to come by, but I still need to see if I can find one with coated caps.
I did some attempted test fitting for the power steering/alternator bracket. Neither the Trailblazer or a truck bracket fit with the pump installed, even though I've see it claimed the truck one will fit. The external reservoir Corvette pump does not bolt to either bracket, but I may try to adapt it. Once concern with that is I'd have to run a much smaller pulley, so could end up overdriving the pump. Another possibility is pulling the reservoir off the Trailblazer pump and seeing if I can adapt it to an external reservoir. Finally, I might see about snagging a Volvo electric pump, but I'd rather avoid the cost.
Retook a bunch of measurements with more precision, and will try to create a basic diagram to make them easier to follow.
Oh yeah, measured the height of the pinch welds of the frame, assuming it would be level in normal operation, and it is angled down in the front. Assuming it would normally be level, that means the transmission may be a bit too high, which is good. The correct way to check would be to measure the angles at the front of the diff and back of the transmission, but my angle finder has gone AWOL. Going to look for it again soon.
Once you factor in the cost of the adapter U-joint might it be cheaper to get a different yoke that's already shorter and uses a cheapter U-joint?
In reply to Stampie :
It is a possibility, but so far I have not found a short enough yoke that I may not have to cut it down. But now that I've done some more digging, I may be able to improve my search criteria. Turns out the u-joint I need may be fairly common, but I haven't found one with coated caps yet. I suspect the ones on the driveshaft are, so if I can remove the yoke from it without damaging the joint, it'll be a matter of which is cheaper, the u-joint or the yoke. I could go with a raw steel u-joint cheaply, and just change it right after the challenge, too, but would rather not.
Looks like the Dana 53022X is under $30 on RA, but it appears uncoated. The GMB 219 - 0356 appears to have some sort of coating, but is about $47. The driveshaft was the biggest question mark in my budget planning spreadsheet, ranging from $0-250, so either is on the low side. A replacement coated Dana 53613X is about $22, so if I can find a proper 1310 yoke below $25 I'm definitely safe on the budget, and if I can get one cheaper than the GMB u-joint, I'm probably safe. There is potentially something to be said about using a factory yoke over a possibly inferior cheap one, even if I have to cut it down.
I re-measured everything, so have more precise, and hopefully, more accurate dimensions. Here's a really crude diagram of the parts:
Assuming the engine/transmission stays at the current location, and a flat seal has the same flange width as a cone seal, I have 28-11/16" between the diff and the transmission. subtract the 26-13/16" of the driveshaft, and that becomes exactly the the 1-7/8" length of distance from the u-joint centerline to the end of the fillet, so in theory the seal would be right at the edge of the correct diameter surface. Additionally, with the 7/8" length of the cone seal removed, the yoke will have 4-1/16" travel into the transmission, so would need to be cut down 1". Of course, that is all with no margin for error.
Since the C-channel will end up fixing the distance between the differential and the engine, there probably does not need to be much extra length. I am betting even moving the engine forward 0.25" would be good enough. However, to be able to remove the driveshaft without unbolting the engine or differential from the chassis, I'd need at least half the radius of the rear-u-joint, so 17/32". I'll be making that decision based on how the oil pan and front accessories will fit at different distances. This will also determine how much the yoke gets cut down (assuming I don't buy a 1310-style replacement).
Next issue up is the motor mount adapters. Moving the engine forward less than an inch from where it is now will cause interference between the lower LS and SBC bolts. Looking at the SBC mount, I think I have a solution.
The blue circles holes are the correct mounting holes. The red circled ones I think are just the holes they use to crimp the clamshells together. If I switch to them, I may be able to get rid of any interference. I'll want to have the engine back out and a good look at the adapter plates before being sure. I will also need to come up with a spacer, or make a raised pedestal on the adapter plate, as the holes are spaced back. This would also be the time to see about whether or not to raise the engine just a bit for clearance.
I still need to find my angle finder, or just give in and buy another one.
Minor updates. Picked up a new angle finder. The transmission is about 2.5 degrees up more than the differential is facing down. A few rough calculations will put the rear of the transmission about 2" down from where it presently is and the front of the crank pulley about 0.4" higher when the angle is corrected. Next time I have time to drag parts out of the garage and unfold the engine hoist, I'll see about lifting the engine enough to remove a 2x6 from the stack under the transmission pan, to get it closer to correct.
In the current configuration, the oil pan can only move forward 0.25" before interfering with the crossmember. That number will get bigger when the drivetrain angle changes, and the engine is sitting at the correct height, but I don't know by how much.
Still haven't got a solid path for the power steering. Leaning a bit more towards either going with the Volvo electric pump, or finding a 5/8" center bore six rib pulley that can be fitted to the Corvette pump, then coming up with a way to adapt it to the Trailblazer's PS/Alt bracket. If I do the latter, I want a pulley that is only a bit smaller in diameter than the smooth one on the pump now. I don't want to overdrive the pump by much. Another possibility is to convert a Saginaw pump to remote reservoir. The main interference issue with the Saginaw pump right now is the steel return line, and I could potentially bend it out of the way. I would also need to come up with a different pressure hose than the stock Vette hose, as it is expecting the outlet to the rack to be on the side of the pump.
Finally, the mount idea above will not work with the adapter plates I already have, so I would need to make new ones. At that point, it would be tempting to just find some cheap poly bushings, buy some tubing and some 1/4" thick plate, and make my own mounts. Might not be any cheaper, and would definitely take longer than making new adapter plates out of aluminum, but it would allow me to make it fit exactly how I want it.
I have a little time to ponder, and maybe wander around a junkyard for ideas. The block hugger headers I ordered won't be here until Saturday, and I don't want to pull the engine back out until I have test fit them.
Vans have remote resivoirs on power steering factory
Dusterbd13 said:Vans have remote resivoirs on power steering factory
Ooh, do they use the same pump style? I'll check yard inventory to see if I can snag one
Yes. Just a remote resivoir. I use the a style on my stock car in place of the truck one
In reply to Dusterbd13 :
Cool, thank you for the idea!
Made some time this morning. I think I made a logic error when measuring the differential angle yesterday. After adjusting the engine/transmission angle, the C-beam was way too close to the tail housing.
Just to satisfy my curiosity, even though the outcome is obvious, I tossed the yoke on.
So that is not going to work.
I think I know what is happening. I've owned a couple 3rd gen F-bodies, and I seem to recall when the torque arm was unbolted from the transmission, the differential wanted to rotate upwards. Which would mean the angle value I captured yesterday for the differential was not its "natural" position. This is a bit of a bummer, because the re-angled drivetrain made vast improvements in the oil pan and crank pulley to crossmember clearance, and make it look like with a bit more room, the truck power steering will fit.
I also got a message that my headers are delayed until Monday. At this point, I will try to think of anything else I want to measure quickly, then I'll pull the engine for now, measure the stock SBC mounts and adapter plates as they are bolted together, and see about coming up with my own engine mount design. I am thinking something similar to these Speedway mounts, just adjusted for the offsets I want. I'm into the current setup for about $36, so some universal poly or rubber bushings and steel tubing and plate should be near budget neutral.
I am just realizing it is also time to pull my band saw apart and figure out what broke the last time I used it.
I believe on every extremely low budget C4 LS swap video I've watched, the builder used the stock transmission, and just bought an adapter flexplate. I'm beginning to understand why.
While you are in the junkyard looking at power steering check out some yokes. I remember on dyintorace's RX7 we swapped yokes to make the driveshaft fit. IIRC the TH400 yoke was shorter than the 4L60e yoke.
In reply to Stampie :
I'll definitely keep an eye out. It appears a lot of GM transmissions used a similar 27 spline yoke. It may be hard to find anything nearby, though. The yard I usually go to has a 70's Chevy truck, but it looks like a 1 ton, so probably has beefier u-joints. There's an 82 Regal there, too, but it uses the newer style u-joint. I'm guessing I need to go back before GM started going metric on everything. Which makes it a little odd that the C4 uses the older joints.
With the engine back out, and everything packed in the garage, there's not a lot of working room. I took some measurements on the driver's side mount and adapter plate, played around in CAD, then generated a mount that should have the same dimensions. I then adjusted it in an attempt to move the engine forward and up 3/8", and the mounting holes inboard 3/8". A few hours later, the 3D printer spit out a test prototype.
This won't be what actually gets used, or even is representative of how a metal one will look, but is only for measurement purposes. Of course, I managed to drop it and damage it on the way to the garage, should not have put that triangle hole in to save pennies worth of material. A little superglue, and it was in good enough shape for the job.
It was also test fitted on the chassis. I used two different stock style mounts as a comparison, since they have a decent amount of variation. I found some repeatable reference points and got out the rulers and tape measure.
Fore/aft - measured from a front LS mount hole to a chassis brace near the front of the car.
Side-to side - measured from center of mount hole to a casting rib on the engine block
Up/down - measured from center of mount hole upwards to a boss on the block
Noting the variances in the two stock mounts, and any tolerances in the mounting holes in general, this is a bit like measuring with a micrometer and cutting with a chainsaw, so I need to accept it won't be perfect. I'll make some minor adjustments and print a second prototype to see if I can get it a little bit better. The fore/aft is really close to the minimum value I'd like to have, and I think if I raise the through bolt mount a bit further off the surface, I can bring the side to side value back out a smidge, while increasing the height of the block. Looking at those numbers, I am wondering if I made a miscalculation somewhere along the line when I was compensating for the aluminum adapter being 5/16" thick and the steel plate I use likely being 1/4" thick. I'll also likely need to make the hole nearest the standoff a bit more oversized, to allow a bolt to fit in the space, or will have to grab a shorter bolt for that one.
Before making the next prototype, I'm going to make a run to the metal store. I think this is enough of a proof of concept to start planning the actual mount. It'll use 3/16" or 1/4" thick steel plate to bolt to the engine, likely some 1/8" for the stand offs, some 2" OD 1/8" wall tubing for the outside, and some 3/4" OD 1/8" wall tubing for the inner sleeves. Bushings will be off the shelf, or I'll try to print them out of TPU. Once the final prototype is made, I'll use it as a reference to cut, drill, and weld the mounts together.
I may have a van power steering pump from the van that donated the 5.3 to the datsun, if I do it's yours if needed. I will poke around later
i may also be able to help with bushings and tube, can see what's left in the big bag of random poly bushings I got on clearance at summit for $10 25 years ago
Thank you for checking! I'm good on metal now, and may order up some bushings to test with, especially if I can get them by the weekend. Would like to have the engine back on for other test fitting as soon as possible. I still need to design the C beam adapter, and make sure all the accessories will fit.
Redesigned prototype. Hoping I have time to print it tonight. If so, I'll retake the measurements above.
In addition to attempting to alter it to shift the engine into a bit better position, I upsized the lower forward hole to 13mm, and added grooves at the centerlines of all the holes, and a few others at spots that should make it much easier to transfer measurements, make templates, and cut and weld it.
New measurements for prototype 2:
Fore/aft: 14-11/16" Average position change: 25/64" forward
Side-to side: 2-1/2" Average position change: 3/8" inward
Up/down: 3-1/8" Average position change: 11/32" downward.
If 1/32" is the biggest deviation from my target values, I'm extremely happy. That is more accurate than my welding skill will allow for. I do need to add a tiny bit of length back to the frame mount. It is a bit loose now, but only needs a little sliver added back in. I've ordered some bushings, but am also running a test print right now to see if making them is viable. If so, I'll move the printer to the garage (TPU fumes are supposedly noticeably worse than PLA), and give it a shot.
Might be in a bit of a holding pattern until the bushings come in, so I can check some unpublished dimensions on them. I'm sure I'll find something to do in the meantime.
Not much happened on it during the weekend, but I did modify my test engine mount and turned it into a guide for cutting and center punching the engine mount plates. Shrunk the holes down to 6 mm, which made it much easier to get a punch in the right place. I just taped it to the steel plate, punched the hole locations, and used a permanent marker to mark where to cut. After that, off to the bandsaw.
I did get pilot holes drilled after this picture. I need to clear a little space near my drill press, and see if it can handle drilling the final holes, or if it is too underpowered, even on its lowest speed setting. If so, I'll swing by a teammate's place sometime, and use their better drill press (Pretty sure everyone on the team has a better drill press than me).
Minor update time. The mount plates are now fully drilled as of yesterday. My drill press barely pulled it off, and it's wobbling was enough I had to upsize the holes a little bit to make sure the plates lined up and bolted to the engine properly.
Here's today's experiment:
The bushing was printed out of TPU with quite a few solid walls and 60% infill so it would have a little bit of give to it. It has a bit more flex than the Prothane bushings I have as a backup, but is way more stiff than rubber. The purchased bushings would be an approximately $35 hit to the budget. This one is using about $1.50 of material, so total cost for them would be about $6. Now I just need to print three more.
Wonder how they will hold up to turbo heat?
Dusterbd13 said:Wonder how they will hold up to turbo heat?
Depends on how close they get. The basic TPU like this loses strength somewhere between 176-212 degrees F. So, if an oddly shaped coupler on the cold side was needed, this might work. There is stuff that can handle higher temperatures, but it's pricier and I think may require more heat than some 3D printers can handle.
There's been a lot of naysaying about using it for engine mounts due to the heat, but from what I've read, the few people who actually have done it have not had problems. That said, if the headers were going to run much closer to these, I wouldn't attempt it.
The challenge build is kind of a practice run to get a feel for working with the material. I figure if I'm ever in a situation where suspension or other bushings are NLA for a project, this stuff could come in handy.
Was trying to have the mounts done today, but that was too ambitious with the time I had. Everything is cut out, and most of it is fitted. The supports for the tubing still need a small amount of grinding. I've been checking them against a template, painting the area that needs to go, and grinding them down, but sometimes the paint flakes off before fitting is done. From the last check, it looks like there isn't much more metal to be removed.
This weekend is looking a little busy, so I probably won't get back to it until Monday.
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