Topic: 1970 D0ZF-C (428) alternator pulley observations

[70cj428]

Also posted this over at the 428CJ site ........

Does anyone here have a 70 428 AC car with a known original Alternator ?  I'm beginning to suspect that all D0ZF-C Alternators were built with a dual sheave pulley and if the car had AC, the second sheave wasn't used. When I got my R code car way back, the original alternator had a dual sheave pulley on it and I just assumed it was off a non AC car. since then I've seen two other original 70 428 AC cars that both also had a dual sheave AC pulley (with one unused sheave). I just bought an ugly but pretty original Q code car (with AC) and it also had it's original D0ZF-C  alternator with a dual sheave pulley. I can't imagine why anyone would have just switched the alternator pulley on this car as it still has it's original water pump, alt, rad, carb, distributor, fuel pump, ect ....

Another reason I think that all 428 cars in 70 got the dual sheave AC pulley is that all the 428 applications used the same part number alternator, and I'm sure the alternator was supplied with the pulley. ( If Ford wanted to use a single sheave pulley, they could have just specified the Boss 302 alternator (D0ZF-A) that's identical to the "C" alternator except it has a single sheave pulley.) 1969 428CJ cars have 2 separate part number alternators, C9ZF-B and C9ZF-C, the only difference being the pulley.....

Thoughts

John

[7Lscjracer]

I'm thinking it's a case of using what pulley was necessary to get correct belt alignment.
Speaking of belt alignment, if you find you need to rebuild that original water pump, make note of the hub depth.
Incorrect hub depth is a common cause of belt misalignment, typical of rebuilds seen with the "fits all" 8 bolt hole hubs.

[J_Speegle]

Looked through my pictures but as you know there aren't allot of AC 70 CJ cars. None of my pictures either had a good angle to see the alternator so deep below the Smog pump or the engines were out

Did the AC equipped cars use a different water pump pulley than the non-AC examples?

[70cj428]

Did the AC equipped cars use a different water pump pulley than the non-AC examples?

Yes, they use the AC belt to drive the smog pump, so they don't have the third smaller sheave on the WP pulley like a non AC CJ does .....

[preaction]

John, I know a few things changes from a 67 390GT to a 70 CJ but a 67 with thermactor and air used a single belt for the air compressor and the smog pump and also used a single pulley for the alternator.

[cobrajet_carl]

I thought the alternator was original on my October Dearborn R code but the pulley and fan are too shiny I think. Which is interesting because I haven't replaced anything on the car and I've had it for 25 years. So the single sheave might not mean anything.

[HDAshmore]

I have an original paint original engine 1970 Dearborn Mach 1, January build.  It is a 351C with AS, PS, PDB and FMX auto.  I pulled the Alternator yesterday, which I believe to be original and it had a 428 double sheave pully on it.  I questioned why also as it is a 351 C car.  I have a picture of the alternator.  I cannot prove it is original but it looks to be and the car is documented only 50K miles from original owner. 


Dan in Kansas

[J_Speegle]

I thought the alternator was original on my October Dearborn R code but the pulley and fan are too shiny I think. Which is interesting because I haven't replaced anything on the car and I've had it for 25 years. So the single sheave might not mean anything.

Yes that alternator and mounting hardware sure don't look to have the same age and residue as the rest of the items in the immediate surrounds

.............. I cannot prove it is original but it looks to be and the car is documented only 50K miles from original owner. 

Though a bit off thread - does it have the original stampings on the front part of the alternator case?

[HDAshmore]

I'll grab it tomorrow at the farm and take detailed pics.  Not sure on answaer without it in front if me. 

[HDAshmore]

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[HDAshmore]

J_Speegle,

Sorry forgot the text in the above post.  The above pics are of the alternator in my 70 Dearborn January build 351C, 4V, AUTO, AC , PS, PDB car.  I believe it is original.  The original owner stated the cars mileage was correct at 60K.  I am not positive on anything as I am learning as I go.  Just found a rolled lip fender on the drivers side so I am scratching my head even more now.  If these pics do not tell anything than I apologize for taking up space and time.

Dan

[J_Speegle]

J_Speegle,

Sorry forgot the text in the above post.  The above pics are of the alternator in my 70 Dearborn January build 351C, 4V, AUTO, AC , PS, PDB car.  I believe it is original.

Did you find the alternator number on the unit?

[HDAshmore]

No, it should be on the top rim, correct?  I haven't seen one yet.  Does that make it replaced at some point? 

[specialed]

13 point c5az fan used from 65 to 69 then 10 point doaz fan. Also would be c9af stamped pulley.

[J_Speegle]

No, it should be on the top rim, correct?  I haven't seen one yet.  Does that make it replaced at some point?

Examples of some stamped 70 alternator cases