TexasHonda

I replaced the timing belt and radiator on my 97 2.5TL today. It took most of the day, beginning at 10:30am and continuing to 8:30pm including cleanup and tool pickup. I thought these notes might be useful to others contemplating timing belt replacement.

Cooling Fans Removal
Cooling fans have to come out to access the timing belt and also for radiator removal. Removing the fans is a real PIA. They have to be removed in sequence beginnig w/ the pax side first and drivers side 2nd. Accessing the wiring supports, connectors, and releasing the connector mounts is difficult and backbreaking work. Patience and persistence is necessary. The PS hose center clamp and support on the thermostat housing have to be removed to provide enough flexibility in the hose to allow the pax side fan to come out. It also helps later to access the crankshaft pulley for restraint and bolt removal. If you haven't removed the PS hose center support on the driver's side cooling fan housing, you may be puzzled as to how it releases. There is a clip you pinch to allow the clamp to slide rearward off a metal bracket. It's not obvious and Acura shop manual doesn't provide any guidance. Wiring harness must be disconnected from PS pressure switch and lower thermoswitch A at the bottom of the radiator. They came off easy.

Radiator Removal
Upper radiator hose is easy. The transmission cooling lines are a bit tricky and have to be released from below the car. They are fleixible and pull off the tubing nipples easy. The lower radiator hose is another significant problem. It was easy enough to squeeze the clamp and relocate up the hose sligltly. However there is little room to wiggle the hose and remove, or even break the hose bond to the radiator outlet end. After much wiggling and pulling, I finally managed to get the lower rad hose off.

Accessory Belts Removal
Once radiator is out, the accessory belts can be removed w/o terrible difficulty. The PS belt is the most difficult and requires laying under the car to loosen the pivot bolt. A wiring harness must be loosened and relocated to access the alternator pivot bolt.

Timing Belt Removal
The big problem now confronts you,...removal of the crankshaft pulley (harmonic balance pulley) retaining bolt. I've had big time problems w/ this bolt on Accord 4-cyls and had to get shop help on a couple of occasions. I have read where some were concerned the 2.5TL crankshaft pulley was special and required a different restraint tool from other Hondas. This is not the case. I used my Schley Honda Harmonic Balancer Restraint Tool and it worked well. The shape of the opening in the 2.5TL crankshaft pulley is different (not a simple hex opening), but the Honda tool works fine in the opening. I was able to install the restraint tool w/ an 18", 1/2" breaker bar engaged in the tool, and the breaker bar braced against the underside on the driver's side. A 24", 1/2" breaker bar and 19mm socket engaged the crankshaft pulley bolt. I had to use a 3-ft cheater pipe slipped over the 24" breaker bar. Leverage was probably about 4-ft. Even then, I had to pull w/ everything I had before the bolt released w/ a loud crack. My 24" breaker bar bowed alarmingly, but held. Boy is that bolt tight! W/ crankshaft pulley removed, you remove the valve cover, upper timing cover, and lower timing cover to expose the timing belt assy. The timing belt and tensioner are easily accessed for removal.

Installing the new timing belt proved challenging. I had the crankshaft and camshaft aligned correctly at TDC on #1, however when I installed the new timing belt one side was taut, other side slack and after turning the crankshaft I found the alignment was not correct; i.e. the camshaft was misaligned when crank was aligned at TDC #1. Here I discovered a procedure that may help others. I installed the crankshaft pulley on the crankshaft and tightened retaining bolt using restraint tool, w/ the timing belt covers OFF. This arrangement allows you to turn the crankshaft and reposition the timing belt w/o removing the crankshaft pulley! I turned the crankshaft to align at TDC#1, loosened the tensioner and locked tensioner in the slack position. I removed the timing belt from camshaft only and rotated camshaft to correct misalignment, a 1-notch rotation. I then re-installed the timing belt on the camshaft, and released the tensioner. After turning the crankshaft several rotations, the alignment was nearly perfect. Don't let anyone tell you that you have to get the crankshaft and camshaft alignments perfect. You only need to get them very close. Some judgement is necessary. Misalignment of over 1-notch on the camshaft pulley is not acceptable. Something less than 1-notch is good, IMO.

I again removed the crankshaft pulley and installed the upper and lower timing belt covers. Reinstall the crankshaft pulley, and properly set the timing belt tensioner through the timing belt cover access hole. Hole oover is tough to reinstall, even w/ grease.

BTW, I cleaned and reinstalled the crankshaft pulley retaining bolt w/ anti-sieze to hopefully easy any future removals. My 1/2" torque wrench only goes to 150 ft-llbs, so I had to estimate the final torque to 180 ft-lbs. I opted not to replace the water pump, and may regret that decision if it doesn't last till next timing belt change.

I note that some plan to run their timing belts well past the 105K replacement interval. I opened my removed tensioner bearing and found the grease was nearly completely dry. Bearing was serviceable if the old grease was removed and replaced. I installed a new tensioner. Tensioner bearing is likely not good for much beyond 10 yrs. I suspect timing belt is good for many more miles than the tensioner. My timing belt looked quite healthy.

Reassembly was tedious but uneventful. Engine seems quieter. I had a little growling noise at 1500-2000 rpm that I thought was AC compressor. It now seems to have stopped, but I haven't had time for a long ride and the noise may return.

Bottom line is the 2.5TL timing belt is not as hard to do as the Honda 4-cyls, but removing the cooling fans offsets that advantage. Net is about the same. I would call it advanced DIY, but w/i the skills of many determined DIY'rs.

Regards

TLBaller

I wish you took pictures while doing the process but this is great as it is!

Ken1997TL

Thank you VERY much for this info Texas!

TexasHonda

Sorry about no pics. When you're up to your elbows in grease w/ grease-covered rubber gloves, it's just not feasible to stop and take pics.

I used a source for my 2.5TL timing belt and tensioner that others might consider. On ebay there is an on-line parts store, Auto-Parts Store run by N V Thai. The timing belt is made by Conti-Tech and seems fine to me, but I don't know if it's poor, adequate, or superior. I've used 2 Conti-Tech belts w/o problems. However, the tensioners from Auto-Parts Store have Koyo bearings, the OEM manufacturer and appear identical to the removed original. Prices are very good, perhaps 1/2 of OEM prices and N V Thai is very good at reducing shipping cost also. Following is his link.

N V Thai Auto Parts

A big lesson-learned for me yesterday was the tensioner. Clearly the tensioner is unlikely to last for 2 timing belt changes and should be changed w/ the timing belt. Many don't do this and may suffer a TB failure when bearing begins to drag and bind.

theloweman

Ive heard of shops using an impact wrench to loosen the crank pulley bolt. Is that a bad idea on these hondas?

TexasHonda

Air impact will work...if you have enough air impact, however all the 1/2" air impacts, that I'm aware of, will not reliably work. The breakout torque is typically in the range of 700-900 ft-lbs. Even the best 1/2" air impacts are only about 500 ft-lbs of reverse torque. This just won't do the job if you have a tight bolt, as most seem to be. That said, I have managed to break the bolt (2.2L Accords w/ same size bolt) w/ a relatlively modest 1/2" air impact, probably 250 ft-lbs capacity, on two occasions. So it may be worth a try. Have a backup plan if the air impact doesn't work.

I believe use of a restraint tool, two good 1/2" breaker bars, and a 3-ft length of 1" or 1-1/4" cheater pipe is the best method for 2.5TL's.

good luck

LDH

I changed out the radiator on my sisters 3.2 this morning and I was wondering if the foam padding that goes around it even matters? The old ones were soaked in coolant and glued on to the stock radiator so I didn't bother taking them off to swap over. But after everything was done it looked kind of funny without it.

Another thing is the car runs a lot cooler now which seems like a good thing, but I'm so use to hearing the radiator fans turn on when I shut off the car from when I still drove it. But I've had the car in my posession all day and I have yet to hear it turn on after shutting the car off, but I know for a fact the fans work because I let the car idle until it finally turned on.

TexasHonda

You can use some foam pipe insulation to "stuff" in the gaps, however getting it to stay in place is tricky. Some adhesive will help.

Make sure the thermoswitch B, which controls the engine off cooling is actually connected. If disconnected the fans won't ever come on w/ engine off and nothing will show up on your ECU either. If thermoswitch B was enabling the fans to come on before, then it's probably working OK.

Is the temperature getting to the "normal" range on the gague, usually just below 1/2 of full range? If not you may need a new thermostat. Too cool operating temps waste fuel also.

good luck

LDH

Thermoswitch B is the one in the radiator right? If so that is connected.

The car after about 30 minutes of driving runs about 3/8ths of the way on the gauge instead of just below 1/2 like before. The fans were so loud before and I learned that one of the bolts holding it on was missing and 2 of the otheres were loose. So the car runs perfectly quiet now, back to how I use to remember it. Thanks for the reply though, I'll look into changing the thermostat if that is really the problem. Is there anyway the coolant mixture would change the temperature the engine runs at?

TexasHonda

Coolant mixture doesn't change coolant fully warmed temperature. The fully warmed position on the dash gauge does differ from vehicle to vehicle, but is generally a good guide to thermostat performance. Only way to know for sure is check the temperature w/ a IR temp gauge. They are cheap and lots of shops have them to perform these checks. I wouldh't change thermostat unless fully warmed temp was less than 180F.

good luck

LDH

everything is back to normal, I guess I just wasn't driving the car enough that day to make the fans turn on. My sister said after driving to work the fans came on when she shut off the car, so everything should be fine for now. Thanks for your help.