Maintenance Schedule for 944 Race Cars
 

OK, so I do not have a speedometer or an odometer.

I was wondering what I should do from a preventative maintenance standpoint.

How often should I:

1) check the belt tension;
2) replace rod bearings;
3) change oil and filter (I know that testing the oil is the best -- an oil expert suggested to me that changing Mobile 1, even in a race car, sooner than every 6 months is probably just a massive waste of money)
4) clean air filter; etc etc etc .

What things should I be doing on a regular basis, and what interval should I do them?

Also, is time/number of events sufficient, or is an hour meter really worth it?

1) Yearly
2) Yearly
3) Figure every 3-4 weekends of track use. Cheap insurance - plus it forces you to get under the car and make sure that everything looks bolted down ;-)
4) Assuming K&N filter- twice a year?
5) Fuel filter - has it ever been changed? Every other year
6) Fuel injectors - yearly
7) Spark plugs - 2x depending on how they look
8) Shifter bushings/shift lever, etc. Yours felt very sloppy - so this is one time thing
9) Tranny oil - yearly, maybe 2x

Others -please add in to this list

I don't think an hour meter is worth it as people run these engines for years without a teardown.

change oil every 3-4 weekends of track use?....
I'd say pull an oil sample at 5-10 track events and see. I'd expect that the expert you consulted is correct, and that even every 6 months is a little bit overkill.
I would just estimate total track time and use that for calculations, I assumed 2 hours per track event (10-20 hours)

Definately keep up on the transmission fluid. If you are changing your oil every 6 months then change your transmission fluid at the same time, or at the worst yearly.

Thanks Guys!

hmmmm. The only thing on this list that I have neglected to this point is spark plugs and transmission oil. How hard is it to change the transmission oil? Is that one of those things that is very easy to change and could/should be done at the track, or is does it involve some PIA clearance issue that makes it easier if the car is on a lift. Also, better done warm or cold . . . I guess I better visit Clark's

Matt, if you though my shifter was sloppy, you should have seen it before. It would flop from side to side in corners! OK, do you have a link to the "fix" that you think my car needs?

What about wheel bearings, rotors, a-arms and cvs? Are those purely inspect and replace/repair as needed or do some people replace on a schedule out of paranoia?

I was gonna say, what about the chassis!?! :)

I repack my wheel bearings every year, replace as needed. Always replace both on each end of the car, of course. Rotors - I get excellent rotor life out of my KFP's, so I've only replaced them once in 7 years (going from old used ones to new). Likewise, I inspect all my spherical bearings for slop at the beginning of the season - including strut mounts. No replacement required yet, and I'm finishing 5 years on the a-arms and 3-4 on the rear trailing arms. Suspension arms are replaced as I bend them (mine are all steel). CV's I repack each year, though I have a full set sitting on the shelf that I'm overdue to install. I've only ever popped them when hitting things or being hit, but did cut a boot once on a loose wire (reverse light switch).

I do like to inspect under the engine after each event; I'm running dino oil, change out all 8 qts after each race weekend. Cheaper than Mobil 1, and yes, it might be able to last longer. I also PAINT ALL CRITICAL SUSPENSION BOLTS with a paint pen, so I can tell at a glance if anything's moved or loosened, without getting out a torque wrench.

Yeah, fresh trans oil once a year. So far, looks like I'm going to need to replace rod bearings every year, mains every other. I'm due for a full rebuild at the end of this year, as she's starting to smoke - so evidently rings are every other year too. Not bad; my motor is not remotely stock, it's fully-built to the limit of class (ITB) rules. It's not pro-built, but might as well be IMO, since we took it right to those limits. Runs REAL loose clearances, makes only adequate oil pressure, never great oil pressure. Most fairly stock motors should be able to get a couple of years on bearings, except of course for the #2 rod bearing concerns on the 2.5.

I seem to recall the expected service life of stainless brake hoses is a couple of years... I think brake calipers may want a rebuild every other year too.

I realign my car (or at least check it) every race.

Fuel and air filter once a year, as with belts; my timing belt is only $8, so it's too cheap not to. :b

We've also recently run into expected life of valve stem seals; I can't get teflon ones, so looks like those will only go a year... :(

Todd,

Transmission fluid is simple, but you will need a 17mm allen head IIRC. Also, get a small fluid pump to get the oil in there. It can be done at the track but I prefer to do it at home on the lift. I've been doing mine twice a year.

As for engine oil, I tend to change mine after every 3-4 track days. Yep that's probably overkill but it allows me to look for metal shavings (ie problems).

I sent my fuel injectors to for cleaning and testing a few weeks back and they needed it!

Now that I have a second engine, my plan is to rebuild one each year and swap them out.

Thanks Vaughan and Tim. Very helpful.

I was going to ask that about the injectors. Would it be sufficient to have the old ones cleaned and inspected in the off season, or is it better just to replace and use the olds as spares?

I put new ones in at the beginning of the season . . .

I have an awesome overkill fluid pump that I received as a present from Griots. Hmmmmm. Maybe I will take it to the track with me and change fluid there.

Any recommendations on brand/weight of transmission fluid?

Also, Vaughan, why on earth use Dino???? Everyone with whom I have spoken says that Mobile 1 is a miracle oil. You will probably save money since you don't need to change so often as dino . . .

I run dyno in my car as well (Rotella). Why, it's cheap and I can change it often to inspect for metal shavings.

As for injectors, if they are cleaned and tested and work fine, why bother replacing?

I run redline tranny fluid 75W90 and mix half with 75W90NS to get better hookup of my LSD.

You guys are a pretty pessimistic bunch, huh? :roflmao:

I change my offroad race bike oil after every ride and I've caught some potential problems prior to a complete meltdown.

TD, IMA will do your injectors for about $100 if you bring them in. $200 if they have to pull them. They'll get them rebuilt to stock for that price. Also, if you want to find some time - leave your car with them for a bit - they'll find you a second easily just in set up and ARE the 944 guys around VA.

Also, they can dyno your shocks and compare with them with Moton's/JRZ's/Bilsteins so you know what your damping looks likes before you spend the big $$

As for the shifter rebuild - try this link:

http://www.tech-session.com/kb/index...x_v2&id=95&c=4

Oh - the procedure I linked to above is to rebuild the shifter. Much easier to replace it with a new part - about $50 for the lever. See the very bottom of the link.

I have generally changed the oil after each race/DE event wknd (typically 2-3 day events, 3-4 hours track time, 3-400 miles). Always used a synthetic, Mobil 1 15-50 and Amsoil 2000 20-50.

I have not done much extra checking or maintenance on the timing belt, other than the recommended intervals (retentions around 2k and 15k, replacements around 30-40k).

I dont have a rod bearing replacement schedule. I have not had a problem up to this point. They get replaced when the engine gets rebuilt.

I would like to change the trans fluid yearly, but have gone a couple years between changes - (usually around 4 events per year). Again synthetic, Mobil 1 75-90, or Amsoil. I do not feel there is the need to change it as often as the engine oil, since the trans does not get any combustion blow-by, or gasoline/solvents into the fluid (which degrades the engine oil).

Brake fluid: I use Ford HD DOT3 fluid, so it will pickup some moisture and significantly drop the boiling point over time, so I will give the car a good flush a couple times a year and a bleeding before each event.

Pads and Rotors: as needed.

Caliper rebuilding: no schedule, just as needed - which has not been very often

I will check the balljoints periodically. Can easily be done anytime you have the car up with the wheels off. I have always replaced control arms with factory new units - I wont use any rebuilds and have not yet invested in a set of Charlie or Fabcar arms.

Wheel bearings: I repack the fronts every couple years; change fronts and rears when needed.

Probably not a bad idea to check the CV axle bolts periodically. I have never had a problem with them, but I hear of guys having them come loose somewhat often.

Tim, back home on the lift? You're making me jealous!!! ;)

I also use Redline in the dif - again, helps the old 951 LSD hook up. Probably more of a concern to change trans fluid when running a clutch LSD than not.

Yes, my oil's real cheap and I can still buy it at the corner auto store - about $3/qt IIRC for 8 qts. I put the good money into a good filter that will trap all that crap - Mann, not Fram. I run Valvoline VR1 racing oil, SAE 40. I started running regular instead of synthetic after running into issues not getting the rings to seat properly. I'm curious to see what the rings and pistons look like now after 2.5 years of racing - JE pistons and Total Seal rings.

Yeah, I'm pessimistic. I'm in this to win races, not build motors again and again...

Party on, dudes!

My routine. (have been doing this for 6 years now)

Maintence
Each session.
Tire pressure check and oil top off.

Daily
-Bleed Brakes and visually inspect.
I get the car on stands bleed the brakes because I like that firm pedal. The other nice thing is to have a chance to do a visual on the underside and suspension. Pretty easy to do check for leaks, bushings, loose bolts, etc. Over the years I have spotted many little 5 min fixes this way and been alerted to other maintence. I also monitor front pad thickness mostly by where the heat zone goes to. Once the head zone gets to the backing plate time to change the pads. (1/3 remaining or so)

- Rotate tires. I also rotate all 4 tires to ensure even tire wear. I HATE wearing one tire more than rest since it destroys the entire set. No matter how good your alignment each track tends to put more stress on certain tires. Run two days at this track and you even up that wear by rotating Sat vs Sunday.

Every 3-4 events
Oil change with filter. I used to change every other event using Mobil 1, but when I went to Amsoil the cost was more and I now sqeeze another event out of the oil. Rather be safe than sorry.

That is about it for routine stuff.
- Brake pads get changed as needed and I always have spare set in parts box so I can change at the track.
- Brake fuild is never "flushed" as when I bleed the brakes daily it flushes through a can evey 10 races or so.
- Wheel bearings... I repack the front when I do rotors as needed every 2-3 years.
- Rod bearings usally every couple years or so
- Tranny fluid proably once every 4 years, should do it more, but I run redline heavyshock proof and it seems fine.
- Paper Air filter gets inspected and major dirt knocked out every couple events. Changed maybe once a year went looks dirty.

As for the rest of the car it is really on an as needed basis. T-belt for example gets check each event, but since I don't have belt covers that check is a 1 min job. I do the belt by feel anyway so I don't need any tools or anything. I do ALOT of visual inspections and listen for any odd noise. My daily morning routine involves many of these simple checks. Doing this also makes me condfident I have solid car underme for the day. BTW... check CV bolts often. Even a simple hand tightness check to make sure they are not backing out. I had it happen to me once and it sucked to miss a race when the 1/2 shaft popped off going down the pit lane for start of the race.
Steel arms are great since there is no "schedule" for them. Keep a spare set in with ball joints in you parts box and do qucik visual. They look bad replace them, otherwise just keep running.

I had my injectors cleaned and balaned a long time ago for $80. Not something I would do often however. I figured at 18-20 year it would be good thing to do.
One of the blessing of the 944 NA is that if you keep the oil level full you probably can get away with not doing much of any maintence work. I know plenty of the 944 spec guys that rarely look at their cars between races and I am the only one I know of that does daily bleeding and visuals. I just prefer it that way. The biggest thing to keep an eye on is oil level and rod bearings. As for the timing belt, well that is good for 5 years and 30k miles. That is an eternity in racing and nothign tells me racing is harder on the t-belt than street use. If you repalce the belt when you do rod bearings you should not need to worry.