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AC7 Turbocharger

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=31157
Printed Date: 24 Jun 2025 at 5:12am
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Topic: AC7 Turbocharger

Posted By: Larry F
Subject: AC7 Turbocharger
Date Posted: 22 May 2011 at 3:38pm

Can I use the 74029309 Turbo in place of the 74027204. The manual calls for the 27204 which I can not find. I have located the 29309. The 29309 is for a later serial nubered engine. This is on a AC 7gb craller. This is information from the manual. The engin serial number is 3D12351.

Thanks in advance.

Replies:

Posted By: Dnoym N. S. Can.
Date Posted: 22 May 2011 at 5:48pm

UA33002 Turbocharger

New T04B90 Model

Replaces number D4029309, 74029309, 74029207,
74036513, 74062751, 84062751, 409080-5009
Includes Mounting Gaskets
(T04B90 Model)
Fits: 7030, 7040, 7045, 7050, 7060,
(210, 220, D21 Air Research Replacement)
BOLT ON REPLACEMENT FOR AIRESEARCH.
IF REPLACING RAY JAY TURBO, LINES & AIR
TUBE NEED TO BE CHANGED OR MODIFIED.

Larry i could not find anything on that
tubo number 74027204.maybe someone
else can help you

hth B:-) Dnoym

Posted By: DrAllis
Date Posted: 22 May 2011 at 9:21pm

If your old turbo is an "AirResearch" brand it probably has a V-clamp holding the compressor housing to the center section. The newer AirResearch turbo doesn't have the V-clamp, but is bolted. They will interchange with a little hardware modification on the oil lines and the rubber hose that connects the air inlet (newer turbo is about an inch shorter). If your old turbo is a "Thompson" or "Rajay" brand, the newer model will also work but you will have to be more creative on your oil lines.....like maybe use a hose for oil return and make a supply line from copper tubing and brass compression connections and fabricate a crossover tube to the intake manifold as well.

Posted By: Larry F
Date Posted: 22 May 2011 at 9:39pm

DrAllis

My Turbo is bolted and has no V clamp. It sounds as if it may have had a new tubo installed at some point. It appears as though the 74029309 replacement will work and I may or may not need to modify the air and oil line. Thank you for the reply.

Larry

Posted By: Larry F
Date Posted: 22 May 2011 at 9:41pm

DrAllis

In addition the old turbo is an Airesearch with no v clamp.

Larry

Posted By: DrAllis
Date Posted: 22 May 2011 at 10:00pm

Then, they may be indentical except for the exhaust housing size/ratio....usual size is a .96 A/R and other sizes make be .84 A/R or .81 A/R.....the smaller numbers are tighter and allow the turbo to "spool up" at a slower RPM. Farm tractors use .96 and spool up at 1700 RPM and high idle at 24-2500 RPM. The size number is stamped on the exhaust housing somewhere is you are able to read it....sometimes inside where the exhaust housing bolts to the manifold.

Posted By: groanwow
Date Posted: 20 Apr 2012 at 1:10am

My knowledge about turbochargers is very poor...thanx for the great post...

It was very informative and useful....

http://www.buyautoparts.com/part/replacement-turbocharger/" rel="nofollow - Turbochargers