Engine/Transmission (1994 - 1998) What shop in Portland ore to go to for a timing check?

[Tim1]

Hey fellas, my 97 is a bit short on power, I think. It has a #12 tst plate in it, but does not go like I think it should. Of course I am used to my 03. With a yard and half of bark dust, seemed to bog her down. Where in Portland Ore would be a good place to get the timing checked and what should it be set at? I did a search, but lots of different numbers. 150k and runs super. Cold not get the signature change to work, something about 300 something? Thanks Tim

 

[Tim1]

got the sig figured out

 

[DAN V]

Call Source Auto in Clackamas. They are of of I-205 and and I think Hwy 224. They have a huge shop. Guys there are great. Had front end work done there a while back.

 

[Bob V]

Yep, Source is the place www.sourceautomotive.biz

 

[Tim1]

Filled the truck with fuel this am and getting 24 miles per gal, I think best to leave the old girl alone. Will talk to source auto on Monday. Tim

 

[hsmith]

24 mpg on a '97 with 373 gears? Better leave it alone.

 

[HSpiering]

Got that right!!!

 

[ata]

On your 97 5 speed the timing is 13. 8 degrees. I had Source Auto move mine up to 16 degrees and gained about 2 mpg highway and 1 mpg in town. Also on your 97 somebody must have changed the gears in it. In 97 you could only get 4. 10 or 3. 54 from the factory.

 

[Tim1]

Ata, that is interesting about the ratios. I asked the po about the gears and he said 3:73. When I had the truck on the hoist,I looked for the tag on the diff cover, but it was not there as it has a mag hiteck cover. At 70 mph I am taching about 2200 rpm if that can say anything. My 92 had 4:10 and at 65 mph, it was wound, so maybe these are 3:54. That would explain why slow pickup with the barkdust. I did notice that 20lbs boost is all she will deliver. Will check the hoses on the boost, or maybe 20 is all they will do with the #12tst plate. Also, I read that Joe Donnely said that 18 degrees is max. Thanks for the reply. Tim

 

[Tim1]

Found the specs and 21-23 psi is about right. So, good there! Tim

 

[cerberusiam]

At 70 mph I am taching about 2200 rpm if that can say anything.

Given tach and speedo is correct and depending on tire size, that is about right for 3. 73's and a 5 speed ratio. If the tire is taller than stock could be 4. 10's. With 3. 54's you should be under 2000 rpms at 70 mph.

You will have to pull the diff cover and look at the ring gear to verify ratio.

 

[ata]

I have the 3. 54's and my engine turns 2150 at 70.

 

[kcv67]

To find your gear ratio. Jack up one side of the rear end mark the tire on the bottom mark the yoke have some one turn the tire one full turn and count how many times the yoke turns. 3 1/2 times 3. 51 3 and 3/4 times 3. 70 4 and a little more 4. 1

Casey

 

[cerberusiam]

LOL, I was wondering when that would show up. Never work correctly running thru the spiders. Have to have a posi and jack up both wheels for it to work correctly

 

[Tim1]

The tire size is stock at 245/75x16. Will try and get a better speed with tach reading, my dash tach is hard to tell. so I will set the tack at 2000 and get the speed. Tim

 

[JSoloman]

Hey Tim,
Unless you really like to monkey with your rig, the guys are right on. Take it to Source. I moved up from Eugene 3 yrs ago and the guys told me about Rip and Bill. I haven't been disappointed. Trust is a biggy for me with my truck and you will get the straight stuff from them.

 

[kcv67]

So do spider gears slip or do they change the gear ratio?

 

[cerberusiam]

So do spider gears slip or do they change the gear ratio?

They don't slip, but, the angular velocity departed to each can vary. The basic rule is a = pb + qc where a is the sum of b and c. p and q are the modifiers in the equation such that if the speed of b and c are not equal they will make it equal to a. Short answer with, 1 wheel on the ground the speed of the axle of the ground is close to twice the speed of input velocity. The only time the jack up the rear end works is with a posi trac that will ensure each wheel turns at the same speed with minimal friction and both wheels have to be off the ground and the plates need to be good and solid. An open or tq bias differential will never yield accurate results either because the friction is never equal side to side no matter where the input is.

The only absolute way to tell the ratio is look at the markings on the ring gear or it is a guess. 3. 73 to 4. 10 to 4. 30 is so close it easy to mistake them.

 

[kcv67]

Sorry for the thread hijack. But I have done the jack method many times and it does work.

Casey

 

[Tim1]

Called Source this afternoon and the fello said will call me back in a few. I guess he meant days. Never called. Oh well. Tim