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Push Rod Failure
https://www.slantsix.org/forum/viewtopic.php?t=24924		 Page 1 of 1
Author:  SpaceFrank [ Sat Sep 15, 2007 1:57 pm ]
Post subject:  Push Rod Failure
Hi Guys,

I was driving my '64 Dart 170 down the highway yesterday when I suddenly noticed a loud metal clanking that varied directly with my RPMs. To make a long story short, after limping home at 20 mph and tearing things apart I found that my two push rods on the #1 cylinder had bent and were sitting down in that "push rod area" (whatever you call it), leaving the rocker arms dangling.

One of the rods had actually cracked, and right where it did so I saw that the side of the rod was shiny from metal-on-metal abrasion. Apparently the little metal cup that houses the spark plug had been wearing against the rods. When previously changing my spark plugs, I've noticed this wear on the cups themselves and never thought much of it. Apparently that's one of those assumptions that gets wrecked by experience.

Is this a common problem with the Slant 6? Have any of you encountered it before? I can replace the push rods fairly easily, but I'm wondering if there's a way to ensure that they won't rub against those spark plug cups in the future.
Author:  SlantSixDan [ Sat Sep 15, 2007 3:19 pm ]
Post subject: 
Only bent pushrods will generally contact the spark plug tube, so it sounds like you had a bent rod long before you had a broken one. Once the rod is bent, the repetitive forces will tend to aggravate the bend and fatigue the metal of the rod until it fails. So, what caused the bend in the first place? The main thing to check for is adequate oiling to the top end. If there's insufficient oil up there, for any of several reasons, the pushrods can bend. How's the rest of the top end look, now you've opened it up? Dry or wet? Crusty or clean?
Author:  SpaceFrank [ Sat Sep 15, 2007 5:30 pm ]
Post subject: 
The top end looked wet with oil and very clean. I rebuilt the whole thing ~3 years ago and put in new rods at that time as well. I did have a moderate oil leak a while back and ran low a few times, however.
Author:  SlantSixDan [ Sun Sep 16, 2007 12:17 pm ]
Post subject: 
Nice set of Isky chrome moly pushrods for the 170 on ebay right now:

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0171288618

All 170s (1960-1969) take the same pushrod, these are listed as "1960-62" because that's when the catalog was printed!
Author:  SpaceFrank [ Sun Sep 16, 2007 4:43 pm ]
Post subject: 
Those look pretty nice. Unfortunately, I have to get the car back on the road ASAP, so I already had the local NAPA ship some in.

By the way, here's a picture of the two bad ones (hopefully I post this correctly):

Image
Author:  Doctor Dodge [ Sun Sep 16, 2007 7:35 pm ]
Post subject: 
Replace the pushrods and check to be sure they do not rub against anything. You may have to change some of the rocker shaft hold-down spacers so that rocker arm is pushed away from the spark plug tube.
DD
Author:  SpaceFrank [ Mon Sep 17, 2007 11:08 pm ]
Post subject: 
Aha, good call. I'll go out and check that tomorrow. How much should the rocker arms be able to move on the shaft, if at all?
Author:  SpaceFrank [ Wed Sep 19, 2007 6:08 pm ]
Post subject: 
AAARRRRRGGGHHHHH

Got the new pushrods in from NAPA today and went to put them in. They are 1.5 in too short. The pushrods currently in my car measure 10" long, and these I got from NAPA are 8 3/8". I checked on that Ebay auction that Dan posted, and the ones listed there are 7 7/8". Either different /6's have different length pushrods, or both NAPA and that Ebay seller have their parts listed incorrectly.

Just to make sure I'm not crazy and actually do have a 170 like I've always thought, I just went down to check the engine number on the block right behind the alternator. The number there is 'V 22 6 29' followed by something that looks like a German cross. I have no idea what this means.
Author:  Joshie225 [ Wed Sep 19, 2007 6:25 pm ]
Post subject: 
If you ordered 170 pushrods and they are 1.5" too short you don't have a 170. You have a 225.

I'm sure Dan will chime in and decode the number you provided.
Author:  Pierre [ Wed Sep 19, 2007 6:56 pm ]
Post subject: 
Copy and pasting from this post,
Quote:
Quote:
New engine numbers
V22 6 29 2
Thanks for the help.
1964-model 225 built on June 29, 1964, 2nd shift.
The "170" you found, was that on the outside somewhere? There were trim levels of 170, 270, etc. that may not of directly correlated to engine size.

The maltese cross means crank bearings were undersized 0.001". I think theres a decoder in the FSM for other letters/symbols.
Author:  SpaceFrank [ Wed Sep 19, 2007 7:24 pm ]
Post subject: 
That is mind-bogglingly awesome. I don't know exactly why I thought I had a 170, but I've been operating under that assumption ever since I've owned the car. Well, I found some 10" /6 pushrods on Ebay an hour ago and they should be air-shipped to me by the weekend.

Thanks for all the input, gentlemen. I'm off to giggle about my newly-discovered engine displacement.

Edit: By the way, the 170 comes from the hood emblem. I guess that denotes trim level rather than engine size.
Author:  SlantSixDan [ Wed Sep 19, 2007 8:30 pm ]
Post subject: 
Tellya whut, there're times I wish I had a 170 in my '62 Lancer. Keeping the 770 in gasoline costs a fortune. ;-)
Author:  icaneat50eggs [ Thu Sep 20, 2007 10:16 pm ]
Post subject: 
Thats the cheapest increase in C.I. you can get. :D
Author:  tophat [ Fri Sep 21, 2007 3:31 pm ]
Post subject: 
Quote:
Tellya whut, there're times I wish I had a 170 in my '62 Lancer. Keeping the 770 in gasoline costs a fortune. ;-)
A 770 ? :shock:

I want one! :D or 3 :D


TopHat
Author:  sandy in BC [ Fri Sep 21, 2007 6:06 pm ]
Post subject: 
Low Block 770.....is that stroked?
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