The Weekly Adventures of Mikuvan: Operation LOST BEARINGS

I solemnly promise to give every major mechanical repair on this thing a cheesy faux-military operation name.

With that aside, I present to the internet my front right wheel bearing:

“Bearing”.

Ever since Mikuvan has been putzing around under power, I’ve noticed a subtle grinding or rumbling noise at low speeds. It’s a consistent noise, didn’t vary too much with power or turning, and all symptoms pointed to a bad bearing on one wheel. While on the lift last week, I confirmed that the wheel was a bit loose, which was a positive diagnosis. Since tapered roller bearings which have obviously lost preload are most likely torn up and damaged, I went ahead and ordered a new set of front wheel bearings, two (a pair) for each wheel.

That was last week. My general assessment was that local driving on the bad bearing wouldn’t be the end of the world, so in this prescribed shipping gap…

Quite a few Van Adventures ensued with whoever was in the building, on the slightest of whims.

And I finally registered the damned thing.

 

I also became a delivery driver for Beantown Taqueria.

…Right, just kidding on that. I don’t know why, but that sign fits the vehicle so well. Anyways, the Beantown folks and us residents of the N5x complex are pretty close, so we pitched a delivery sign on the roof one afternoon for giggles.

I also spent some time shopping it around to area auto body repair places to get estimates for repainting and rust patching. Conclusion: …yeah, um, I better learn to love Bondo.  Typical estimates ran in the 3 to 6 thousand range for the full repair, of varying degrees of shady – from fiberglass and filler to custom shaped steel with body solder filling.

Now, I could be trusted to weld a few steel plates in place, but not to make anything look pretty. Left to my own devices, I’d just rattle-can white over the repairs, which would just look like ass. I’m currently debating heavily the make-versus-buy scenario thusly. At the very least, a good white repaint is not out of the question.

Fast forward to Thursday morning, when I was rained on by packages.

There’s a few things from Rock Auto here. First, my new bearings. Second, on the same order, I got a replacement front heater/AC blower motor, and after testing the 3-speed fan circuit with another motor determined the 3-speed resistor block was also damaged (missing speed 1), so there’s also a replacement for that too.

And in a separate order, a replacement annoying thing:

While on a shopping spree, I decided to take care of the power mirror switch too. This cost $5 and actually came from a early 90s Mitsubishi 3000GT. Back in the days when cars shared parts (and all the parts were square…)

(For the Internet record: ’91-’94 Mitsubishi 3000GT power mirror switch fits a ’89 Mitsubishi Vanwagon and presumably ’87 and ’88 too.)

I got cracking as soon as all the white collar folk in the building left for the day so there was parking lot and loading zone space cleared up. The goal was to do both bearings by sundown.

Right. I barely got through disassembling one side by that point, but onwards…

Step 1 is to clean that which has seemingly never been cleaned. I was armed with not less than three cans of brake cleaner – the good kind, with the tetrawhateverthatcanceris, and ended up needing all of them. There was brake dust cakes everywhere. Even the brake dust had brake dust on it. I’m sorry, Earth.

After removing the external dust cap, I realized I forgot one thing: The shop manual.

Now, I basically knew the procedure as “remove the fingery nut thing and take off the hub, check if bearings are present; if they are, add grease to everything in sight and retighten the fingery nut”. This and a few on-site Youtube videos later, I decided to just keep freelancing it.

The shown image is an expression of my gratitute for whoever designed the T-handle right angle drive ratchet that I will not stop spamming until all my friends have one. This thing really is a godsend. I had maybe 15 degrees of motion to loosen the mounting bolts for the brake caliper, and undoing the entire screw like that would have been tortuous. Instead, you break the bolt’s connection and then crank on the little T-handle.

Caliper is loosened and secured out of the way…

And now I’ve removed the castellated nut, the pin holding it in place, and the grease retainer washer. The outer bearing cone proceeds to fall out naturally with a quick tap.

As soon as I pick it up, it rains everywhere:

Here’s both cones removed. The big one is the inner bearing, and it’s not in bad shape, but I’ll replace anyway. The outer cone, though, is a textbook case in metal fatigue!

The previous service round used some red grease which made this entire scene look like some kind of horrific back-alley surgery, which…

…well, it was.

I decided to clean out all the old grease in the hub since it was most likely full of metal powders and chips from the ruined bearing, which would be counterproductive to use a new bearing in. About half a roll of shop towels and another can of cleaner was dedicated to this task alone.

After the degreasing, I found this brilliant example of fatigue-induced spalling. One of the features of the bearing rumble I heard was a regular clicking or detent kind of noise. Well now I know what it is.

There’s an entire field of engineering study dedicated to how bearings fail and how to make them less fail, and it is really quite enjoyable to read around the literature (for me, anyway). Here’s a great page by Timken (and a newer one) illustrating common tapered roller bearing failures. Distressingly enough, the failure most resembles the localized “pinched housing” failure, though it really could have been caused by improper installation when the vehicle was last serviced this way – a well placed punch from driving the ring in and out could have cracked it sight unseen.

How could you mess up installation? Apparently, many ways.

The Official Strategy Guide recommended taking a brass rod and punching (with a hammer) the races in and out for installation. The trouble is, I tried that. For half an hour, to basically no avail. The brass would just dent and deform instead of driving the outer race. I did have to resort to a steel punch in the end to take the rings out. If someone tried the reverse, I easily see how you could trash a bearing by microscopically shattering it.

To get my new races in, I had to make a pressing jig on the lathe from chunks of aluminum – of the proper diameter to press on the ring entirely, and long enough to reach down into the hub, then pitch it on a 3 ton arbor press with me basically hanging off the bar.

How is Tony Stark supposed to be able to do this? In a cave? With a box of scraps?!

With the new rings pressed, it was time to start on the long road to reassembly. I was basically, according to the Internet, grease-slam everything in sight, mashing it into the bearing rollers and pumping the hub full of the stuff. Sounds good.

Full disclosure: I didn’t have a tube of real honest-to-locknuts “nice grease”. That was a minor oversight of sorts. I grabbed from MITERS a bucket of white (presumably lithium) grease that at least had a picture of a car on it. For what specifically, it didn’t say, but the other tubes of lithium grease all said “Not recommended for use in wheel bearings”. Okay.

I don’t exactly mind having to do this in 10,000 miles. We’re assuming I won’t blow it up by then.

The Official Guide also warned against reusing the back side grease seal (which rides on a fluid barrier of grease at all times and keeps the stuff inside contained), but The Internet spoke contrarily this time. Not having a new grease seal, I cleaned and kept it since it appeared to be in good condition – wasn’t torn or feathered or otherwise seeming to not contain grease any time soon.

Torquing the adjust-a-nut to spec. 22 ft-lbs in, untighten, 8 ft-lbs in, then back out to the nearest castle slot for the locking pin. This part I remembered from reading the Official Guide earlier. This is when I’m glad I decided to buy the “I’m sure I’ll need this soon” +1 Torque Wrench of Not Overcranking.

Retaining hardware remounted…

Wait, so you’re saying the only thing preventing the wheel from popping off is a little 5/8″ nut?

If I designed cars, this axle spindle would be a single 3″ diameter shoulder screw.

Finally, a last wad of grease in the dust cap and the reassembly is done. Spins freely and doesn’t wobble – better than when I started I suppose.

About this time when I was sticking my head in the wheelwell to place the brake caliper bolts, I noticed that the secondary A/C condenser fan had basically fallen off the fan motor. Well that’s why it’s making so much noise…

The arrow points to the torn-ass remains of the fan hub. This condenser assembly might be the first to go in terms of parts permanently being dismounted.

Caliper remounted and checked for clean rotation.

Say, how much do I need to torque those lug nuts? 100 ft-lb. My torque wrench doesn’t even go up that high. That amount of torque is basically me standing on the end of the thing.

The front right wheel is now all buttoned up again. I had started around 6:30 – it was now 10:30 and I decided to leave the front left for the weekend. Yeah, you’re supposed to do them both at once, but it’s going to be 95 degrees tomorrow and I’m not doing this outside again. However, now that I know the exact order of operations and have pressing jigs ready, I’m confident I can do the other side in under an hour.

After cleaning everything up, I went on a few rounds of the surrounding area and some loops in a parking lot to check for more noises. The cabin is much quieter now that I’m not grinding metal on metal directly into it. No other bearings are making sounds, and as far as I can tell the suspension isn’t creaking either.

Next on my list is that damned fan motor. Did I mention it’s going to be 95 tomorrow?

 

 

Long Live Mikuvan

In the past few days, basically from Sunday to Thursday, I’ve managed to put something like 150 miles on Mikuvan, which is no small feat for purely local – Boston, Cambridge, and associated suburbs driving outside of regular daily commuting. For me, the “daily commute” is something like 1.1 miles by scooter, so for the most part said driving consisted of helping friends move large objects – it being end-of-semester moveout season, picking up more cruft on Craigslist, and purposefully going way too far westwards just to grab lunch (I sincerely recommend Blue Ribbon BBQ in West Newton). And even participating in helping search for a stolen car, but that’s a story for another day.

All in the name of Science, of course – I’ve pretty much been doing all this just to observe the vehicle’s behavior under different driving conditions, ranging from highway to extremely low speed start-stop city driving, to the occasional stoplight pull which will remain undiscussed.

I haven’t been able to break it. For all intents and purposes, Mikuvan is a fully functional car. There hasn’t been any stalling or overheating, no more fluid leaks, no rough shifting or other transmission business. There’s quirks and worn parts typical of a car about as old as I am – the front blower is not functional and the power mirror (oh boy, power mirrors!) switch is also broken, and the air conditioning belt isn’t hooked up (and I’m sure the system is totally drained too). Plus, those rust patches.

The de facto beginning of summer was marked by the start of incessant rain, after which I assume it will actually get warmer. I took the opportunity to give the whole outside a proper washdown, aided by the rain. It had been living under a tree for a month or more, so there was tree drippings and bird shit everywhere, and other environmental deposits.

 

Lookin’ pretty good. I got rid of most of the grunge from the presumed side-swipe damage on the left lower bodywork also.

One of the nice features of the great N5x building complex, where MITERS and other shop-nests are, is that there is a two-post auto lift installed in the area where the automotive racing teams (FSAE, Solar Car, et. al) work out of. Many students have used it in the past for wrenching on personal cars, and I now join those ranks:

I ran into an interesting problem in that my wheelbase was too short to swing the lift arms under the frame. To fit, I had to remove one pair of lift pads (one is at the end of each arm), swing the front set under, manually push the van a few inches back to clear the rear set, and then reinstall the pads in-place.

The goal of hovering Mikuvan was to perform a full mechanical inspection of the underside as well as to clean the engine and transmission to locate the source of a very small but persistent oil leak.

The belly of the beast, front to the lower right. The engine seems to have been burning or leaking (…or both?) oil for a long time, so there were “sludge bunnies” as we called them everywhere. Most of the underside frame near the engine is coated in a thick sludge film. I suspect it has helpful anti-rust properties, but still. Eww.

For the uninitiated, Mikuvan is actually mid-engined and rear wheel drive. The engine and transmission center of gravity is a few inches rearward from the front axle.

Here’s the underside rear. The clean spot to the left was where the spare tire lived; I had removed this because the rim itself was basically rusted out, and also removed the tire hanger in the process. It’s also where I think the eventual Siemens 1PV5135 will live. There’s many big square frame rails to attach things to in this region. Attachment strategies have been floating in my head and are varied – one part of me thinks I should just buy or Procure Through Alternative Channel a Borg-Warner eGearDrive, a transaxle designed to mate with  the Siemens motor. The other part thinks flipping the diff around and mounting the motor longitudinally (shaft pointing front-back), with an external 2:1 custom reduction, would be better. The differential is a native 4.22:1, so an external 2:1 is almost perfect.

A minor third opinion is to use the guts of the former Mercury Milan hybrid transmission from the old Electric Vehicle Team project, the ELEVEN. It’s basically an embedded eGearDrive, but just a pile of eGears that would require a custom housing. But it comes with a roughly 8:1 total ratio and a parallel-drive (not right angle) differential.

Using several cans of carb, brake, engine, and colonic cleaner, I gave the underside powertrain components a scrubdown. Every once in a while, I’d notice a new dot of oil on the ground while performing pre-drive fluid checks. With the engine and transmission so coated in junk, it was hard to see where it could have been coming from. Hopefully, now, I’ll see a little dark brown slick or something from the point of leakage.

While scrubbing the transmission, I actually found the nameplate! It had been so thoroughly coated I haven’t even noticed it was there.

Interesting enough, the first Google ping for “4G64 AW03-72L” (my model of engine and transmission) is this very theraputic and fascinating teardown video, set to… Christmas music? I’d get to about the 7:00 point and then have exactly shit clue about how to get it all back together.

While lifted, I also went around to the wheels and checked suspension and bearings. Nothing seemed obviously bad about the suspension, but I’m also not a professional suspension inspector. The rubber bushings were not cracked or looking otherwise fatigued.

The bad bearing up front has been confirmed – the front right wheel is a tiny bit loose in all directions. If there’s one thing I know about most car axles, it’s that they use tapered roller bearings which must be preloaded (forced together at all times), so any wobble at all is a bad sign. The alleged (now confirmed) bad bearing had been manifesting itself as a rumbling noise at moderate speeds. I haven’t noticed that wheel center becoming substantially hotter, but I’m also not keen on waiting until that point.

No other wheels were found to be loose, but so long as I’m taking one side apart, the other side will also be replaced at the same time. Guess I know what’s coming up next!

the long term plan

While I was initially excited about taking the summer to get most of the way through an electric conversion, I’m now further in support of the second thought – keep the engine for now, and address all the little mechanical and electrical problems first. Get it in good mechanical shape first, patch the rust holes, and fix the accessories. That way, when I do finally manage to grenade the engine or commit fully and drop it, the rest of the vehicle is ready and able to drive right away with a new power system. Whereas currently, even if I were to somehow install the electric powertrain tomorrow, I’d still be faced with a bad wheel bearing, no front fans (forget even air conditioning!), body rust holes, and such things. Since I don’t depend on a car for daily commuting, I can afford it to be a science project and learn how to address these issues.

Plus, as long as I’m paying insurance on it, it might as well be functional and automotive and stuff. My policy is set to expire, with option to renew, at the end of October, which coincides nicely with the season that Mikuvan should not be on the road to avoid further rust spot damage from road salt (if those have not already been sealed by then).

I think the battle plan will be something like this, in no particular order

High priority

  1. Front wheel bearings – replace Real Soon
  2. All brake system inspection, front and rear, probably to coincide with bearing work since the wheels need to come off anyway.
  3. Front heater/AC blower. It’s one thing to not have air conditioning, it’s another to not have moving air or defrost/defogging. There’s already been a sweltering 80-something degree day in Boston, and it will only get worse from here. Unfortunately this seems to be a deep dashboard dissection job (by the Official Strategy Guide, anyway).

Low priority

  1. Underside body rust holes. Not sure how confident I am on this one, since it would require cutting into the bodywork – luckily in a place where nobody can see me mess it up! The side holes seem to be easily patchable with some steel sheet. The two wheelwell area rust holes are a different story since they will require signficant patching, filling, and contouring. And painting. What? Making something look nice?! This is one job which I may actually throw at a body shop and then hide.
  2. Fix the swivelly-slidy seats, which currently can’t latch into position on the slidy-axis. Currently held in place by a toolbox and a milk crate.
  3. Actual professional repaint of the exterior; the paint in some spots is clearly falling apart, and there’s minor rust patches on the rear hatch where it’s bubbling away around them.
  4. The power mirror switch
  5. Some upholstery which could use replacing, especially up near the driver and passenger footwells where there may also be more rust hiding