When I started our 1988 "760" Turbo to move it out the driveway in order to replace the head gasket (it was overheating and consuming coolant) the timing belt (which was due for replacement) broke. After replacing the head, I tried to remove the pulley from the auxiliary shaft in order to replace the seal before I put the timing belt on. I noticed to my horror that I could not turn the pulley more that about 10 - 15 degrees although I remember that it turned freely when I started taking things apart. I remember that I wanted to remove the pulley but I couldn't break the bolt loose because I hadn't discovered how to hold the pulley. However, since the timing belt had broken just before I began the head gasket replacement, I am beginning to doubt my memory (and my sanity). I am now able to turn the auxiliary shaft by hand in a counter clockwise direction (as viewed from the front), but with a bit more resistance than there should be (compared to the car that donated the head). I can also turn it counter clockwise by hand for a little bit. When I turn it clockwise by hand it sticks in two positions that are 180 degrees apart. Once it is stuck, I have to pull hard on a 1/2 drive swing handle to break it loose even though I was turning the pulley easily by the hand into the position where it got stuck. When I turn it clockwise the oil pump pumps oil (I have the filter off so I can see the oil coming out). I am now fairly sure the auxiliary shaft caused the timing belt to break. There is about a tooth and a half of motion when the shaft is stuck.

• If the oil pump was seized how much would I be able to move the auxiliary shaft?
• Can I pull the pan & oil pump without pulling the engine out of the car?

 

Look at the belt, any teeth that have sheared off near the break mean something broke it. Lots of cracking and no missing teeth mean it just broke by itself.
*Unlikely something mechanical jammed the oil pump, the crossover pipe may have lost it's seal and seized the pump due lack of lube.
*About 10-15 degrees.
*Yes.
*If the oil pump is seized, putting a lot of torque through the aux shaft nut isn't going to hurt it, you will be replacing it anyway.

Whatever is wrong, you will be pulling the oilpan to find the problem.

Regards, Andrew.

 

Sweet Patooty...sounds like you got doo doo coming from every direction. The belt broke last summer? The story seems familiar somehow. Hey, if you have to pull the head and now the oil pan, give serious thought to pulling the entire engine. Much easier to work on. Besides, w/ a blown HG, there's the chance the bearings on the jackshaft are toast and that's why it won't turn...all in all, I'd say pull the motor.

 

The belt broke about 4 weeks ago after the car had been parked for 2 days.

I now able to turn the auxiliary shaft by hand in a counter clockwise direction (as viewed from the front), but with a bit more resistance than there should be (compared to the car that donated the head). I can also turn it counter clockwise by hand for a little bit. When I turn it clockwise by hand it sticks in two positions that are 180 degrees apart. Once it is stuck, I have to pull hard on a 1/2 drive swing handle to break it loose even though I was turning the pulley easily by the hand into the position where it got stuck. When I turn it clockwise the oil pump pumps oil (I have the filter off so I can see the oil coming out). I am now fairly sure the auxiliary shaft caused the timing belt to break. There is about a tooth and a half of motion when the shaft is stuck.

Unfortunately, I discovered the problem with the auxiliary shaft after I put a used head on and bolted it down.

 

Any update?

 

Swiftjustice 44 asked

I have decided to swap in the engine from an 1985 740 turbo, but I cannot separate the engine from the transmission. I am trying to pull just the engine.

• I have checked 3 times to ensure that I have removed all the bolts. 2 at the top, the 2 starter bolts (I couldn't pull one all the way out), 2 on the right (exhaust) side and 2 at the bottom.
• I have unbolted the torque converter from the flex plate.

If I ever get the engine out, I will check the oil pump. The auxiliary shaft turns backwards with a little bit more resistance than normal and gets stuck every 180 degrees when turning forwards.

 

I'm sure you know there are guide pins/alignment pins where the engine/bellhousing meet. sometimes it takes a giant screwdriver to gently work each side free. Personally, I like to pull the transmission and engine together and install them together. An exception would be a freshly painted engine bay that I didn't want to scratch up. Those are all the bolts...the engine's all free, hmm?

 

I got them apart by pulling on the engine lift with a come-along. I am doing this in the back yard so I am on neither smooth or level ground. I suspect it was the dowel pins that were hanging it up

The oil pump was seized. The "gears" inside it look fine, but I had to hammer the oil pump shaft out. There is a significant circumferential gouge in the hole that the shaft runs in, about 5 to 8 mm above the bottom end of the hole and a little bit of scuffing on the shaft.

Now that the pump is out, the auxiliary shaft turns freely, so I think the auxiliary shaft bearings are and oil pump drive gears OK. Some of the plastic from part of the oil separator that hangs down into the opening above the oil pump drive gear was broken off. The sump etc looked fairly filthy to me, but then most of my engine rebuilding experience has been Formula Ford 1600s (dry sump and probably less than 24 hours running time between rebuilds) rather than cars with 300,000 plus kilometers.

I thought about that, but I didn't look forward to wrestling an automatic without a proper transmission jack. I may have a different opinion when it I install the transplant engine.

 

There's been many a time when my chest was the transmission jack, hence my fondness late in life for stabbing them together!