Transmission is in!!


On Monday, I traveled to Tom’s house to pick up the transmission.  He found a couple other defective parts since I helped him dissassemble the tranny and all was well now.  The shifter linkage was way off so he adjusted that.  He also recommended a couple things for me to do.  One was to replace the pilot bushing with a pilot roller bearing.  Two reasons for that:  one was that the existing bushing was probably damaged because of the bearing going out on the main shaft causing wobble and two was that he feels a pilot roller bearing is easier on a transmission than a pilot bushing. 

His other recommendation was to add four ounces of lubrisol to the ATF in the tranny.  You can get it at a GM dealership where it is known as positraction additive.  Years ago when he was doing transmissions for Trans-Am, he told one of the teams he was supporting to add this additive.  They questioned why, but he told them it was his transmission and, if it failed, he would give them another tranny.  They picked up 2mph on the longest straight without making any other changes to the car.

My son, Matt, has the weekend off from his duties as simulation engineer for the #83 Red Bull NASCAR team.  He volunteered to help put the transmission in yesterday.  I had installed the pilot bearing and the flywheel.  Since we did not know if it had been done, Matt had brought his gauge so we could check the alignment on the bellhousing.  When he mounted the bellhousing, he noticed that it was very loose on the dowel pins.  Upon inspection, we discovered that the dowel pins were recessed too far and the bellhousing was actually resting on the tapered part.    We then found a steel rod that we modified so we could get to the back of the dowel pins so we could move them so more pin was exposed. 

After doing that, we had a heck of a time getting the bolts started as the holes did not line up well.  Which is probably why someone had pushed the dowel pins in.  Once we finally had it bolted to the block, Matt hooked up his gauge and I had the honor of rotating the engine numerous times as he did the measurements.  The alignment was off over 1/8th of in inch. 

We had discovered why the transmission had failed.  With the combination of the alignment being that far off and the bellhousing not being secured on the dowel pins, the tranny was moving all over the place, especially under heavier load.  I passed this info on to Tom Huber and he agreed with us.  Originally when Tom heard of the problem in the tranny, he suspected low fluid.  However, upon dissasembling it, he did not discover evidence of it having been a fluid issue as the gears were in good shape. 

Now we had to find a bellhousing, which we did at a place about 30 minutes from my house.  We also bought two sets of offset dowel pins to use in the alignment procedure.  The initial measurements on it showed it to be out about ten thousandths.  After positioning the offset dowel pins, we were able to easily get it in tolerance of five thousandths.  We took the bellhousing off, installed the Centerforce dual friction clutch, and then re-installed the bellhousing.  The rest of the installation went well and we were ready to start the car and see if everthing worked. 

I lowered the car on the lift so the wheels were off the ground and all the gears worked.  We only had the engine running long enough to do these checks, but when we looked under the car, there was a big oil puddle.  We soon determined that the oil was coming from the top of the engine.  It did not take long to find the problem.  The oil pressure sender had been mounted with a 45 degree elbow to get it away from the distributor.  When the engine dropped down after removing the transmission, the sender had hit the firewall and split the fitting.  A friend had the proper fitting which I installed about 8:00 yesterday evening after Matt had gone home. 

This morning I started it with the expected smoke pouring off the headers for about five minutes or so, even though we had wiped everything down the night before and that morning.  I took the car for a test drive and everything worked great.  Previous to the rebuild, when I was in sixth gear and suddenly let off the gas, the car would jerk back and forth so much that I either downshifted or pushed in the clutch.  Happily, that is gone now, which was further evidence of the tranny moving about on those dowel pins.

Many thanks to Matt for helping out and to my neighbor Reese for lending us his tranny jack (again) and for offering a helping hand as we installed the tranny.  Also thanks to Rick for giving me the fitting.

So, it is done and I now wait for the next thing to fix!!!

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