Cushion Hitches when Cat first came out with them

[621_Rocker]

When Caterpillar first came out with cushion hitches were they offered as an option on some of the models? Also, did Caterpillar offer update kits for installing cushion hitches on earlier machines? I am asking this as I have seen 621A models with a cushion hitch although nothing has been shown in the parts manuals. Did people do their own home brew updates or was this something that Caterpillar offered as I hear they offered a 3306 update kit to replace the V-8 in the 621A. Is there any reference available for all the Caterpillar updates that they have offered for all of their machines?

I appreaciate in information that can be provided on this.

Thanks

621 Rocker

 

[Gavin84w]

Initially cushion hitch was an option on 21,s 31,s and the like but then found it,s way into the std model i think in maybe late 21 a models and late 31 b.

Cat occasionally put together special service magazines that list all updates for a range of models etc but you would have to have a old dealer guy who knows his stuff to dig that up for you or a younger guy with a passion for the past!!

 

[JDOFMEMI]

I ran a 623 A model (not really labeled "A", but it was not a "B", and if you don't call it something, it confuses even more people) with a V-8 for a while. It had a cushion hitch, and I always liked it better than the "B" models. You had to run them differently because of the different power curve on the V-8 as opposed to the inline 6 in the newer machines.
Not really sure on the year, but I think it was around 1969 or 70 when the cushion hitch was first available. If I remember when I get back where my Cat performance handbooks are stored I might be able to tell.

 

[621_Rocker]

Jerry:

>(not really labeled "A", but it was not a "B", and if you don't call it something, it confuses even more people)

My exact thoughts.

I would like to find "Caterpillar Service Reporter Magazine" of that era to read more about this. I would like to find someone, a dealer, or a library that has a collection of these. Were they put out on microfiche as well?

I have a 38th edition (2008) Cat performance handbook and it lists 2 early model 621s. 43H series and a 23H series. All the information I have ever seen only lists the 23H series except this mention in the handbook.

Here is the information on the 23H v. the 43H:

23H 43H
'65-'74 '65-'72
300HP 300HP
identical capacities
55,000lbs. 62,600lbs. (difference of 7,600lbs.)
38'1" length 39'5" length (difference of 1'4")
11'7" width 11'10" Width (difference of 3")
11'2" height 11'4" Height (difference of 2")
6'10" tread width 7'3" tread width (difference of 5")
Tire size identical.
Weight on drivers identical.
42'6" turning circle 37'8" turning circle (difference of 4'10")

The 43H is a longer, wider, and heavier machine with a shorter turning circle. Does anyone know anything about this 43H machine? Like I say I have never seen one offered for sale or parts manuals for sale. Something must be different in the hitch/steering linkage to account for the difference in turning circle.

Jerry could you elaborate on the D336 DOHC V-8. How was it to run? Looking at the parts books I have never seen something with so many timing gears. I have heard that they are great when they are running. Definately don't over rev them or let them get down on coolant. Apparently when they are rebuilt they are not as good as new and they have a lot of problems at that point.

Did Cat have a lot of problems with all of their DOHC V engines of this era and go back to the inline push rod engines?

621 Rocker

 

[bruce oz]

j621

hello 621_Rocker ,below is link with the info you are after ,bruce oz

43h in caterpillar serial number shows it as a j621 which is a elevated scraper,


http://www.contrafedpublishing.co.nz/Historical/Classic+Motorscrapers/Elevating+The+Caterpillar+J621.html



.

 

[bruce oz]

ch

hello ,i have a new product feature from caterpillar dated nov 15 1968 with the new models fitted with cushion hitches .
first introduced on the 631b 13g03489 (1967) is now standard on 641 ,651, 657 .
it show that non cushion was the option available with the new models
,it shows serial number for cushion h and non cushion h ,
havnt been able to find any info retro fitted cushion hitches ,
11 pages on the new cushion hitch workings if you would like to see it ,
bruce oz

 

[Neil D]

627 cushion hitch

I have a 627 68M series built during 1970 with a hard hitch-I recently looked at another from the same build year but had a cushion hitch fitted.

Anybody any info on boosting the front 3306's?

Neil

 

[bobin35]

I have a 627 68M series built during 1970 with a hard hitch-I recently looked at another from the same build year but had a cushion hitch fitted.

Anybody any info on boosting the front 3306's?

Neil

I installed a 3306 aftercooled engine in a 627 that had the D333 in it piece of cake really!

 

[621_Rocker]

Bruce,

Thanks for the information. The specs in contrafed article more closely match the 43H as listed in my performance handbook but there are 3 621 paddlewheels listed in machinery trader in the 23H series.

>11 pages on the new cushion hitch workings if you would like to see it

I would like to see it.

My next question would be where is the parts manuals for these cushion hitched 621As. Do they use the same parts as the 621Bs, steering follow up and etc. ? Can a person covert a 621A to a cushion hitch with 621 B parts and is there a parts list and instruction set from Cat for doing it?

> have a 627 68M series built during 1970 with a hard hitch-I recently looked at another from the same build year but had a cushion hitch fitted.

Bobin: my performance handbook only lists a model 627 as series 54K from '68-'74.n It lists the first series of 637 as 65M and 631C as 67M, and 633C as 66M.

Maybe some of this Cat literature is incomplete and inaccurate. I have a service manual for the 631D and it has supplements in it that cover the 631D, 633D, 637D and 639D. There is no listing in the performance handbook of a 639D. I suspect that Cat was contemplating building (and might have built prototypes) of a twin engine paddlewheel in the 63* class. Twin engine paddlewheels can be very useful such as a twin engine Michigan 110 that I have ran. I have ran a 623G quite a bit in poor soil conditions and needing nudged by a dozer.

Thanks for all of the responses to my inqury.

621 Rocker

 

[bruce oz]

639d

hello 621_Rocker ,there is a 639d twin elevated (88x) 31yds(99x)36yds
.built from 1980-85 .700hp ,bruce oz

 

[Neil D]

3306

Bobin 35-you are correct as the 3306 is the follow on to the D333

Any idea what hp your 3306 was making? What was the engine originally installed in ? What was the 627 like to operate after this?

621rocker-I have all the relevant manuals for my 627 and a 54K is a standard scraper without push pull fitted whereas a 68M is a push pull model.


I have been talking with a mate of mine about fitting cushion hitch to this 627 basically all the parts are interchangable between the various 621/623/627 varients. My advice would be to buy a complete cushion hitch unit from a breakers taking note of the serial number of the machine it came off .

Anybody else re-engined 627's?

Neil

 

[sawz5]

i worked in a machine shop in pekin,il in 1968 that made parts for cat cushion hitches. i don't know what models they were made to fit, but it might give you an idea of the time line for the machines they fit. rick

 

[alan627b]

To Muddy the waters Further

Some later 621B's, and 627B's with auger scrapers had 3406's instead of
3306's....you better believe they have a power differrence!
Couldn't tell you what the serial number difference (if any) was...627B's were probably 15S series....I've seen a few 621A's on Machinerytrader.com with 3406's as well.
alan627b

 

[WabcoMan]

Cushion Hitch

Cushion Hitch was developed originally for the 631B series machines to cure a chronic stress problem in the hitch which was causing them to fatigue crack and break in half (usually with disastrous consequences).
It was introduced in 1967 and cured the problem.
It was progressively introduced across the rest of the range (originally as an option and later as standard) on all the 2-axle scrapers except for the 613.

Clark-Michigan had already been investigating axle suspension for their 2-axle scrapers prior to the Cat cushion hitch appearing.

Cats marketing people must have had a field day - marketing a deficiency as a plus when they discovered that cushion hitch gave the operator a better ride as well:beatsme

 

[ronnie]

wabcoman none of the 615's i been on has no coushion hitch they have shocks on the axle that raises like the newer terex scrapers

 

[JDOFMEMI]

At the time it was developed and spread to all models, the 615 did not exist. The 615 has Terex style suspension axle.
Cushion hitch = shock absorber for the dirt
Suspension axle = shock absorber for the operator

 

[ronnie]

jerry thanks for gettin me straight on that for the last 22yrs. i thought it was for my comfort what about the 619 paddle pan what yr were they built

 

[WabcoMan]

J619

Hi Ronnie,

The Caterpillar J619 elevator was offered from late 1963 thru to early 1965 when it was replaced by the J621.
Caterpillar never offered cushion hitch for the 619C or J619 ointhead

 

[DPete]

The cushion hitch is about the best thing that ever happened to larger Cat scrapers, my hat's off to who ever designed it. Not only does it take the shock off the hitch and tractor but allows travel in at least one higher gear. If you add that up over the machines life it pays for itself many times over. We had an old 621J ridgid hitch where I used to work, uh,what a ride

 

[Dug Overburden]

J621 w Detriot Diesel 8V71

If you scope in to read the article about engine replacement in J621's with 3306's & 3406's it also mentions one re powered with a 8V71 Detroit Diesel. Either that machine made it to San Diego Ca to F.J. Willert Contracting or their are two, as this article was written in Australia. I saw the machine many times & always looked for a Terex or Wabco to go by, but was surprised to see a Cat with a 2 cycle D.D. Don't know if it survived the California shake out of non emission's compliant machines

hello 621_Rocker ,below is link with the info you are after ,bruce oz

43h in caterpillar serial number shows it as a j621 which is a elevated scraper,


http://www.contrafedpublishing.co.nz/Historical/Classic+Motorscrapers/Elevating+The+Caterpillar+J621.html



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