Monday, May 18, 2009

Tacoma Mx

The Tacoma is getting close to 200,000 miles. None of the things I blog about (hang gliding, mountain biking, photography, etc) would happen without the Tacoma so I figured it deserved some attention. I have abused it in conditions ranging from aggressive city driving, sweltering desert heat, Arctic alpine blizzards, to 4x4 "roads" to hang gliding sites that a battle tank couldn't get up. I thought a good use of my downtime following my PRP injection (see PRP Injection Post) would be to do a 100,o00 mile service. The list included replacing:

Timing Belt
Water Pump
Thermostat
Power Steering Belt
AC Belt
Alternator Belt
Oil and Filter
Transmission Oil
Transfer Oil
Front Differential Oil
Rear Differential Oil
Brake Fluid
Clutch Fluid
Coolant
Radiator Hoses

After that I installed my freshly powder coated bull bar, front hang glider rack, and driving lights.

My Dad used to say that with the proper instructions, the right tools, and a little confidence you can do any mechanical job. I had never dug that deep into the Tacoma engine before and was a little nervous, but the $2000 Boulder Toyota wanted to do the job was good motivation. I time budgeted a day to complete the job and 6 short days later with Jonny V's help it was done!

Part of the delay was making constant trips to the hardware or auto parts store for everything from replacement bolts, new crush washers, random sockets that I didn't have, etc. Every bolt and nut was seized from a 100,000 miles of heat, cold, and hard use making simple steps take
hours to accomplish.

Making Room of the Tacoma's Extended Garage Stay


Struggling with the Engine Block Coolant Drain Plug


Got It, but I Blew a Vain in my Forehead


Drive Belts and Accessories, Fan and Fan Shroud, Top Timing Belt Cover Removed


When I got to the crank shaft pulley I ran into problems. The Factory Service Manual calls for a special tool to hold the crank shaft pulley while you loosen the pulley nut. 4x4 Wire forums shows how to weld the tool up yourself, but I didn't have a welder so I tried to make one out of laminated wood and drill bits.

My Homemade Special Tool




The specified torque for this nut is 217 foot pounds, but after 100,000 miles of use it needed much more to break it. The wood just wasn't strong enough and exploded as Jon and I tried to break it. I've never seen wood fail in this way and energy released as it exploded was impressive. Luckily, no one got hurt!

My Tool After the Explosion


I decided to stick to my Dad's words of wisdom and order the Toyota special service tool. It wasn't cheap, but I was still well under what the dealer would have cost. The nut was so tight that I had to use a 6 foot breaker bar on the tool to break the nut. A Thule rack bar fit perfect.

Toyota Special Service Tool



6 Foot Breaker Bar


With the crank shaft pulley finally off I could remove the lower timing belt cover and expose the belt. A pair of scissors made quick work of removing the belt and saved me a few more disassembly steps.

Timing Belt Exposed


And Removed


The thermostat and water pump were next. The water pump is the weak link of the system and main reason to do the service. Tacoma's have a non-interference belt, meaning that if it breaks the engine won't self destruct, so you could feasibly drive until the belt fails with no repercussions other than a tow truck ride home. The water pump isn't has strong, it usually fails way before the belt causing the engine to overheat and flood the belts and accessories with coolant.

Old Thermostat and Water Pump



New Water Pump and Thermostat



After the water pump, it was time to install the new belt. I used a special tensioning tool to hold the belt tensioner while I installed the belt. It was a bitch, but after much struggling I got it on with all of the alignment marks lined up with the marks on the cam shafts and crank shaft. This is very important because if one of the cams or crank shaft was one tooth off the engine would self destruct. After the belt was on I turned the engine by hand a complete revolution of the belt to make sure it wasn't slipping. Something peculiar happened, the belt marks were all exactly one tooth to the right of the cam shaft marks. It was consistent on each pulley, but it didn't seem right. Was the belt slipping? After much discussion with Jon of the physics of belts and gears a search on the Internet revealed that this is normal.

Special Belt Tensioner Tool


New Timing Belt Installed


Belt Marks One Tooth to the Right After a Full Revolution


Next it was time to put it all back together. I needed the 6 foot breaker bar on the special tool to torque the crank shaft pulley to 217 foot pounds. The order of the belts was particularly confusing, it took several tries to get them on in the right order.

Installing the Crank Shaft Pulley



New Drive Belts


With the engine back together the brake and gear oil changes were next. Most people don't bother changing their brake fluid, but it is important. The BMW club won't let cars on the track without fresh brake fluid each day. This is done in about 20 minutes with a pressurized one man bleeder. It screws on to the reservoir and pressurizes the system so that the old fluid can be bled out of the slave cylinders. Since you don't need someone to pump the brake pedal there is no chance of sucking air into the system or damaging the master cylinder seals. I wanted to adapt the bleeder to do the Tacoma, but unlike European cars it doesn't have a threaded reservoir cap. I improvised an adapter out of an old brake reservoir cap and some hose clamps.

One Man Brake Bleeder


My Improvised Toyota Adapter



When I tested it to see how much pressure it would hold, it seemed to work beautifully. Then at about 10 psi the cap exploded off the reservoir showering me with brake fluid. Luckily, I had covered the cap with a towel so none of the corrosive fluid got on my paint. The reason it exploded was that the hose clamp was too narrow to hold the two-piece cap together. After searching for new cap that would work I decided on the simplest solution, another hose clamp. It worked perfect.

Two Hose Clamps


Bleeding the System


The total cost for everything including special tools and $140 worth of Royal Purple Gear oil was just over $600, which put me $1400 under the dealer. Like all new mechanical projects it took way longer than I thought, but now that I know what I'm doing next time it will go much quicker. Jo and I just got back from a road trip to Taos, NM and the Tacoma purred like a kitten the whole time.

5 comments:

James Butler said...

Just buy our T100. Much less work. For you we will only raise the price $300. New windsheild. New tires, 109 K miles.. You know you want it.

Lee said...

I hate that most of your posts make me feel so lazy!

Anonymous said...

I would be interested in knowing where you bought the service tool. I've called 3 dealerships in my area and they all say the same "that's a dealer only tool not sold to the public." I don't have access to a welder and don't know any Toyota Dealer mechanics. Where did you get it?

Anonymous said...

I just finished a timing belt change. Two lessons learned for a stuck bolt on the crankshaft pulley heat it first for 5 minutes with a propane torch...will come off like butter. For the tension pulley just lower it, place the belt and then tighten it back up.

willkeim said...

Hey, did you have to completely remove the A/C compressor and the power steering pump. The Factory Service Manual says that I have to do that, but I can't understand why. Is the only reason to replace the drive belts? Couldn't I adjust the tensioners to do that and not have to remove the compressor and the power steering pump? Or are they physically in the way of you removing something related to the timing belt?