VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 1928 vs 1928 dash cluster

Question - are the inner dash ovals the same size between ”˜28 & ”˜29? The ”˜28 oval that holds the gauges appears 1/4” smaller in size. Could I have a different year dash/cowl?

The 1929 dash cluster I have measures 12 5/8” wide and 5” high .

Easiest way to tell between 28 & 29 dash ovals. 29 has 2 extra holes in the lower section of the insert for advance and throttle cables.

Jack - Thank you for the measurement, it is a '29 dash that I am working on. Just picked up a '29 dash plate real cheap on Ebay, so all is good. I am hoping all the '28 gauges are interchangeable with the '29 dash plate.

Steelin Time - further confirmation - it has the two extra holes on the dash plate as well.....

Many thanks for the guys down under.

Hey Mike,

So on top of the differences listed above between a '28 dash and a '29 is that the hole on the right hand side is where the electrolock ignition switch is mounted and is quite a bit larger for the '29. On the '28 that ignition switch is on the column. As far as the actual gauges the oil/ampmeter I believe is the same, the speedometer has some subtle external differences but will have slightly different calibration due to the differential ratios, and the '29 added the heat sensor to the light switch gauge insert. I have both '28, and '29 vehicles.

Are you putting together a '29, or modifying one of your '28s?

Art

Art, a friend of mine was bitten to own a speedster after riding in mine. We managed to secure 3 frames, two motors, a small collection of fenders and doors. We only needed one frame and engine so the rest will find its way to the for sale section very soon. It has a ”˜28 cowl but the dash looks like a ”˜29. Motor and frame is all ”˜281

That should work well. Share some pictures when you get a chance. It would be nice if you can find a '29 differential gear set with the higher ratio.

Art

. Hi Mike, Are you working on a 1928 passenger or One Ton? Here are some pumpkin gear ratios I've garnered from various parts books; Passenger cars and light commercial are 490 thru 1924 is 3.77 pinion = 9 teeth, Ring gear = 34. (Exception is Copper Cooled that had 9/40 = 4.44 ratio ) From 1925 - 29 = 3.82 = 11/42. 1930 and newer used 4.11 = 9/37 with other options.
The utility trucks Model T was worm drive with 7:1 ratio. Model "G" = 6.333 = 6/38. 1923 - 1928 = 7/38 = 5.43 standard with 6.333 optional. 1929 LQ only used 4.875 = 8/39. 1930 - 2002 utility used 5.43 standard with 6.17 = 6/37 optional.
.More gear info web page <http://home.znet.com/c1937/RPM.htm> . Lou .
.

There is also a 11/46 ratio for 1925-29 = 4.18. I have that ratio in my 28 coach.

. GM offered different ratios for special uses. All the final drive ratio information I have including those I have inspected, for the 1927 & 28 passenger cars, have 11/42 (3.82) final drive. But one piece of literature <https://www.gmheritagecenter.com/do...mation-kits/Chevrolet/1928-Chevrolet.pdf> lists 11/46 for all passenger cars. I can only assume that lower ratios were for mountain regions. Higher ratios for the plains states.
. The 6 cylinder parts book list a 9/39 (4.33 ratio) available for 1932 only. There are probably other ratio's available so I only mentioned the Standard ratios in my previous post. .
. Lou
.

Hello coachman28,

Lou and I have an agreement to disagree on one point in his info, usually I find his responses are well researched and spot on in advice. The true '28 ratio from the factory is exactly as you said 4.18/1. Find the specifications for the '28 model in "the old car manual online project". The zone warehouse replacement gear set that could be used in the '25 to '29 differential is the 3.82/1 ratio. The 3.82/1 ratio was original for '27, and '29 but since the '28 was a bigger and heavier car than the '27 the decision was made by the engineers to incorporate a ratio that the 4 cylinder engine could more readily pull. Have some '28 gear sets been replaced with the 3.82/1 ratio? Absolutely. But most in fairly original cars will be the original 4.18/1 ratio in my opinion. Changing to the 3.82/1 in a '28 car is only going to help by about 10%, or 5 mph. Most people don't think it is worth the effort and expense. But all of this is off track of the original posting about instrument cluster differences between a '28, and a '29 so should probably be put to rest.

Art

. Since Coachman has 11/46 gears in his 28 and I have 11/42 in my 28 ABs, and the GM heritage link in my last post suggest 11/46 and parts book in first picture below prints 11/42, I can only assume that both were available. .
. The second and third pictures are a ring and pinion I removed from a 28 years ago. There are 42 teeth on the ring gear, if you care to count. I beg Art's forgiveness in doubting that the 11/46 was available on 28 ABs.
. .
. The fourth picture is a 28 Dash Oval. Controls include: Horn button, Spark & Throttle above steering wheel. Ingition switch locking steering column. Choke and light switch on left of dash. Speedo in center. Amp & Oil gauge and optional cigar lighter on right.
. The last picture is a 29 Dash Oval. The dimmer switch is on the floor. The Choke, Throttle, Spark & pop out ign are on the dash oval along with the Temperature gauge and light switch on the Left side. Speedo in center. Amp & Oil gauge remain on right.
. Lou ,

working with a friend making a speedster. We have a pile of fenders, doors, frames left over. Will post soon