'67 L79 Power Steering belts

[Dennis O.]

I thiught I'd start a new thread because the old one was getting so intertwined even I could hardly find my way around it. It concerns my '67 coupe with L79 and power steering. My car has the short belt that goes around tyhe crank pulley and the power steering pump, and not around the water pump pulley like an L79 with power steering should. I was able to get to tyhe shop and take some pictures of the setup. Perhaps they may help. At first it looked to me like the L79 water pump pulley had 3 grooves, but now I'm not sure since the quality of the drawings isn't very good. I have also added a picture of the Power Steering pump pulley because someone asked.

Water Pump 040.jpgWater Pump 042.jpgWater Pump 041.jpg

[Scott S.]

Re: '67 L79 Power Steering belts

Dennis,

First thing, it appears that you have the wrong power steering pump pulley. On UPC N40-A6, the power steering pump pulley (without C60) is Item 4, GM 3834720. I believe it is cast iron. If you do a search for part number 3834720 on eBay, you will see five examples, it is a three-spoke pulley, and almost certainly has a different alignment characteristic than whatever pulley you have now. The examples on eBay do have the GM part number stamped into the pulley.

[Scott S.]

Re: '67 L79 Power Steering belts

Dennis,

Your water pump pulley should be GM 3890419. eBay pictures show that the part number should be stamped on the visible outer surface, so it should be easy to verify without taking anything apart. The crankshaft pulley should be GM 3858533 BJ, which will be stamped on the front side of the flat center section, you might be able to verify this part number with a mirror and flashlight. (edit: unless it is behind a single-groove add-on pulley)

The Assembly Manual shows that your alternator pulley should be GM 3875968, but this is another AIM error, your alternator pulley should be the larger deep groove pulley GM 3829387. Photos on eBay (there are currently five available) show that NOS examples don't have the part number stamped on the pulley, but a claimed original has 3829387 AI stamped on the pulley and the current reproduction (also on eBay) is also stamped 3829387 AI.

[William C.]

Re: '67 L79 Power Steering belts

Dennis..See attached picsdd 007.jpgdd 008.jpgdd 010.jpg..Bill

[Scott S.]

Re: '67 L79 Power Steering belts

It might just be a trick of the viewing angle in the photo, but if the water pump and crankshaft pulleys are the correct part numbers and in proper alignment with each other, it sure looks like the power steering pump pulley is sticking out way too far towards the front of the car, and it appears that there is an add-on pulley inserted into the center depression of the crankshaft pulley, making for three grooves at the crankshaft location, with the "middle" groove unused, corresponding to the forward groove of the water pump pulley, which is also unused.

If this is an accurate description of the current pulley set-up, and the WP and CS pulleys are correct, then replacing your current PS pump pulley with a correct GM 3834720 pulley should bring the belt into alignment with the forward groove of the WP and CS pulley and you can discard the single-groove add-on pulley currently installed at the crankshaft location.

If I'm seeing what I think I'm seeing...

[Michael M.]

Re: '67 L79 Power Steering belts

Hi Dennis,

I have a 66 L79 w/power steering and no AC. The cast 3 spoke pulley is offset back toward the pump body, as you can see from Bill's photo. The offset aligns it with the second groove (from the engine) of the crank pulley. The front groove is an add-on for other applications (AC?). You can get the correct used pulley on ebay and repros from LI Corvette and Corvette Central, among others. It's the same pulley 65-67. I'm having trouble posting photos, but Bill's photos are the same as I would have posted.

Mike

[Dennis O.]

Re: '67 L79 Power Steering belts

Thanks a lot to all who responded. I now have a chance to correct an at least 25 year incorrect repair. I'll be pulling the power steering pump to make sure it is correct, and will proceed from there.

[Brian M.]

Re: '67 L79 Power Steering belts

Check the configuration of the Alt bracket. I believe the upper bracket should be on the other side of the ear.

[Scott S.]

Re: '67 L79 Power Steering belts

Check the configuration of the Alt bracket. I believe the upper bracket should be on the other side of the ear.

Good call, Brian.

That has to cause an alignment issue. If the alternator pulley is correctly aligned with the rear groove of the water pump pulley, then the alternator bracket has either been bent, or it is the wrong alternator bracket. The picture makes it look like the alternator pulley groove is to the rear of the WP pulley groove, which would be corrected (at least somewhat) if the alternator bracket was attached on the other side of the alternator ear, but it's hard to be sure about angles in the picture.

[Joe L.]

Re: '67 L79 Power Steering belts

I thiught I'd start a new thread because the old one was getting so intertwined even I could hardly find my way around it. It concerns my '67 coupe with L79 and power steering. My car has the short belt that goes around tyhe crank pulley and the power steering pump, and not around the water pump pulley like an L79 with power steering should. I was able to get to tyhe shop and take some pictures of the setup. Perhaps they may help. At first it looked to me like the L79 water pump pulley had 3 grooves, but now I'm not sure since the quality of the drawings isn't very good. I have also added a picture of the Power Steering pump pulley because someone asked.

[ATTACH=CONFIG]39784[/ATTACH][ATTACH=CONFIG]39786[/ATTACH][ATTACH=CONFIG]39785[/ATTACH]

Dennis------



You have an incorrect pulley set on the engine. This pulley set is the one that would be used for the 300 HP engine, although I'm not sure the alternator pulley would even be correct for that application (but I can't see it well enough to say for sure).

I would say that one of two things occurred here:

1) The engine is not an original L-79 although it might be partially converted to L-79 configuration. If it were a 300 HP it would have the correct pulley set (with the caveat of the alternator pulley). I consider this the most likely scenario;

OR

2) The engine is an L-79 and had power steering added. When this occurred the entire pulley set was changed to the 300 HP set. The problem is I don't see why anyone would do this since they could have used the existing pullies. So, why change the whole pulley set?

[Dennis O.]

Re: '67 L79 Power Steering belts

Thanks for all the help guys. It looks like I purchased what is going to turn out to be a very expensive power steering belt. I would say scenario 2 above is the correct one, as the car has what look to be correct stampings and a 6000 redline tachometer. If they bought an entire power steering setup from a 300 HP car, they would have gotten the PS pump with the wrong pulley and would have had to change the rest of the stuff accordingly, if I understand what you're telling me.

[Michael M.]

Re: '67 L79 Power Steering belts

Hi Dennis,

Someone may have replaced your pump with a pump that had the wrong pulley, who knows. They usually don't last 45 years, but it is possible. What is the two letter code for your engine? I think the L79 code is the same with or without power steering unless the car has AC or AIR. The pulley for your car is around $100 for a repro or reconditioned. Maybe less for a used one. You may be able to get one from David Sokolowski in Southern California 310-329-5334. I've had good luck getting used parts from him for a 66.

Mike

[Joe L.]

Re: '67 L79 Power Steering belts

Thanks for all the help guys. It looks like I purchased what is going to turn out to be a very expensive power steering belt. I would say scenario 2 above is the correct one, as the car has what look to be correct stampings and a 6000 redline tachometer. If they bought an entire power steering setup from a 300 HP car, they would have gotten the PS pump with the wrong pulley and would have had to change the rest of the stuff accordingly, if I understand what you're telling me.

Dennis------


Yes, what you suggest is likely what happened if you are convinced the engine is an original L-79. Generally, folks add power steering by purchasing a kit of the correct components, but it's very possible someone bought the system off of another car and transferred all the components. A few things I should have been clearer on:

1) The system you have installed while not correct is 100% functional (as has been well proven in your case, anyway). The deep groove pullies are not essential or, in most cases, even necessary;

2) The pulley system for 300 HP with N-40 is completely different than that for L-79 with N-40. You cannot "mix-and-match" any of the pullies.

3) The power steering pump in your photo appears to be correct in configuration. There are some subtle differences in 63-66 pumps versus 67-74 but these differences are virtually indiscernable with the pump mounted in the car.

One more thing: the harmonic balancer on this engine looks like it has been replaced. Original balancers were not painted black and no SERVICE balancer of the correct part number that I've ever seen was painted black either. The harmonic balancer is one of the "visual cues" that allows one to differentiate a 300 hp from an L-79.

[Dennis O.]

Re: '67 L79 Power Steering belts

The guy who rebuilt the balancer painted it black; I decided not to strip it because I drive the car quite a bit. And for general information, the engine suffix is "HT". I will be on the lookout for the proper parts so that I can get this back to correct.

[Scott S.]

Re: '67 L79 Power Steering belts

Joe,

I just realized that the AIM and Mark Gorney's pulley chart are in conflict on another pulley on N40-A6. The bottom LH drawing on N40-A6 calls out item 8 WP pulley, GM 3890419, but Mark shows that WP pulley is for L79 + N40 + C60, so GM 3890419 is NOT a deep-groove pulley, which means that N40-A6 is in error again, if I understand correctly.


Dennis,

(if I have this wrong, someone please correct me):

To correct my earlier error (post 3), Mark Gorney's pulley chart shows the correct WP pulley for L79 + N40 is GM 3770245. I looked up GM 3770245 (check eBay, there are several) and it does not look like the WP pulley in your pictures, but the wrong pulley, GM 3890419 does look like the WP pulley in your pictures.

The blueprints for the following pulleys are printed on page 23 of the Corvette Restorer, Volume 36, Number 3, Winter 2010:

GM 3829387 (alternator pulley for L79 + N40)
GM 3858533 (crankshaft pulley for L79 + N40)
GM 3770245 (water pump pulley for L79 + N40)

If I have it right this time, the addition of the cast iron GM 3834720 PS pump pulley should complete the pulley set for L79 + N40.

Mark Gorney's pulley chart was published in the Spring 2009 issue of Corvette Restorer (Volume 35, number 4). I think he has posted an updated/corrected pulley chart here on the TDB since that time, but page 19 of the Spring 2009 Restorer shows the same pulley set up for the L79 + N40 option combo as shown on his updated pulley chart.