345 engines

[wpapke]

I am missing my chevy manual so I have no idea what exact engine and trannie my "new" 345 has. Anybody have an idea?

[wpapke]

uh duh, my "new" 1988 345.

[klattu]

Chevy/GM 454 c.i. big block.
400 Turbohydramatic 3 speed, non-overdrive.

Most common.

Freds Airstream Archive can supply much info.

[str8strm]

Originally Posted by wpapke

I am missing my chevy manual so I have no idea what exact engine and trannie my "new" 345 has. Anybody have an idea?

I assume that you have the same "big block" chevy that I have, which is the 454. Mine is an '85 345. Sorry I don't know which tranny it is. TH 350 or 400 I think. I'm sure one of the sharp guys will chime in soon. How about some pictures of your new toy? Ron

[GlenCoombe]

Welcome Ron, hope we'll get a chance to see your "new" 345 at Hiawassee in April....
How many miles? Project or ready to camp? Photos??? Detail!! We love the details.

[swebster]

I agree with all...but I think the 345s had a TH475 (version of the TH400) tranny.

Welcome to the club!

[mustang]

Never heard of that engine But I do Know in most applications they havent used the TH350 or Th 400 in years. I think in 80 they switched to metric trannys then upgraded themm to the 200 R4 And 700 R4 made adjustments to them. Then changed the design to the E460LE and E480 Le.
also the allison tranny Most differences can be determined by the Pan. That would be the best way to tell or Have the dealer parts dept pull what is known as a aquarious.... Like the star sign on the vehicle and they can give you the chassis Build sheet for that Unit

[wascobob]

Steven is correct---The transmission is a TH475, which is the heavy duty version on the Th400. It has straight cut gears in first and second---suposed to be stronger. They are pretty tough transmissions.

The engine is the Chevy 454 and is rated at about 230 hp and about 340 ft. lb. of torque at about 3200 rpm if I remember correctly. Some of the 1988 motorhomes had a carburater (as mine does) and some may be fuel injected, depending on the manufacture date of the chassis. If injected, it might have slightly more power and torque that the carburated version (not sure).

The rear end should be the Dana 70HD with disk brakes and a final ratio of 4.56 to one. At least that is what is under mine.

Hope this helps-------Bob

[buckwheat]

from 1993 Chevrolet Motor Home Chassis Service Guide...
(you need the chassis VIN for this, not the AS VIN)
example from our 1987 345 (with 1986 P30 chassis):
1GBKP37W6G3325116
1 = US built
G = GM manufactured
B = Chevrolet incomplete
K = 14,001 to 16,000 GVWR
P = Forward control cab 4x2 drive
3 = 1 ton series
7 = Motor home chassis
W = 7.4L (454) V8 4BBL gas
6 = check digit
G = 1986 year of manufacture
3 = Detroit, MI assembly plant

From this data and other charts in the manual, the 454 from 1982 to 1989 had 240 HP @ 3800 RPM and 375 ft-lbs @ 3200 RPM. The rear end gear ratio is 4:10 for 16000 GVWR vehicles equipped with 7.4L gas engines. The transmission is a TH475 through 1990, a three speed automatic with the following gear ratios:
1st - 2.48
2nd - 1.48
3rd - 1.00
Reverse - 2.10

Probably more info than you wanted but it sure can't hurt.

[choctawmel]

well, no wander you guys get better gas mileage then me. MY '86 (85 chassis) 34.5 has 4.56 rear-end gears.
In my Chevy chassis manual that puts my GCVW at 19,000 pounds, but I read somewhere the the Th400/475 is only rated at 16,500 GCVW which is why mine has a Allison 545 rated at 32,000 GCVW. Maybe I need to change my rear gears.

[buckwheat]

That's the tricky part, just what is the GCVW of these 345 beasties? Without getting up and braving the sub-freezing temps outside at the moment and finding the weight tag, I really don't know. One thread on here mentioned an aluminum tag on one of the rear differential cover bolts that shows exactly what the gear ratio is. My tag shows 4.10, but I get only 7 MPG on a good day and that's keeping the throttle between 55 and 62 MPH. I recently found and repaired a vacuum leak coming off the engine to the A/C dash controls. I'm hoping that will improve it at least a little. I've still got the stock carb, intake, exhaust, and ignition. I'm dreaming that one day I can get the mods in place to take me down the road at the unheard of 10 MPG that GlenCoombe routinely enjoys. What's the secret Glenn?

[buckwheat]

Here's the thread, nice picture further down on the tag. Maybe I need to revisit what I think I have, 7 MPG really rots!
http://www.airforums.com/forum...0-a-19467.html

[swebster]

I've been getting a consistant 9 mpg without my toad and 8 with in our 345. The biggest difference in mileage came when I installed headers and a free flow 2 1/2" exhaust. I also rebuilt the carb, replaced all of the vacuum lines, removed all of the smog pumps and replaced the ignition (stock).

The other big change I made was to drive at or below 60 mph on almost every trip. I would like to upgrade to either a four speed tranny, or install a Gear Vendors along with fuel injection. I think if I could drop the RPMs down to about 2200 at 65 things would be just about perfect.

Of course...that's only if I don't do the full diesel someday

[wpapke]

Ron,

Will post some picks as soon as i get the thermos bottle out of the shop. am having new shocks installed. wanted bilsteins but the rv shop i went to couldn't figure out which ones to use so we opted for ranchos. by the way, i got 6.5 mpg bringing it up to atlanta from the lot in florida.

[GlenCoombe]

Well 10 mpg is a stretch. I checked it on the way to Floirda last week and was getting 8.5 mpg at 65-68 mph (2900-3000rpm) without the genset running. If I slow down I can get it up to 9-9.5 but I look at time as being money. A GearVendor unit would be nice.... so would a lottery winning ticket.... my wish list is sooooooo long.

[choctawmel]

Well, I guess I shouldn't cry too much. I get 6-7 pulling my Suzuki and it don't matter it I go 55 or 70, I get 6-7.
I threw the carb, smog pumps, and all the vacuum lines to them in the recycle bin and installed TBI. That delivered my sliver bullet from a pitiful, powerless 4mpg. I also have the complete Banks intake/exhaust system.
It is getting close to needing an overhaul or do I see Diesel in my furture?
Mel

[wpapke]

So I had the ranchos installed as well as the roadmeaster sway bar, bilstein dampener, steer safe and new bell cranks. drives much better and doesn't porpoise like it did. now the alternator doesn't carry enough load to drive the lights,and turn signals at the same time. the air horns that are brand new from camping world has a bad connection ... will this never end? The brake hoses were just replaced at CW and the brakes were supposedly fixed which i assumed meant bled but my rear ending of a SUV because the brake pedal went to the floor on a panic stop kind of clued me that they didn't bleed them. so now i'm sitting at my sister's in Mandarin, FL and looking for a repisr shop that actually repairs things! anybody no anyone within fifty miles of here? CW says they only install and don't repair. Nice job if you can get it.I'm beginning to think i should have bought a new winnebago or something.

[str8strm]

You will go thru a phase of repairing little things and occasionally a big one but then you will have soo many trouble free trips the pain of the repairs will fade away. I had ours out today to get fuel and install a "T" in the propane line so we can run a "fire dancer" off it and got compliments everywhere I stopped. Debbie
PS what is CW going to do about not bleeding your brakes?? also you might want to PM Lewster--he might have a suggestion of a FLorida shop

[overlander63]

Originally Posted by wpapke

So I had the ranchos installed as well as the roadmeaster sway bar, bilstein dampener, steer safe and new bell cranks. drives much better and doesn't porpoise like it did. now the alternator doesn't carry enough load to drive the lights,and turn signals at the same time. the air horns that are brand new from camping world has a bad connection ... will this never end? The brake hoses were just replaced at CW and the brakes were supposedly fixed which i assumed meant bled but my rear ending of a SUV because the brake pedal went to the floor on a panic stop kind of clued me that they didn't bleed them. so now i'm sitting at my sister's in Mandarin, FL and looking for a repisr shop that actually repairs things! anybody no anyone within fifty miles of here? CW says they only install and don't repair. Nice job if you can get it.I'm beginning to think i should have bought a new winnebago or something.

Sounds like you may have a Camping World problem, and not an Airstream problem.
The alternator issue has been addressed here, many people have installed LED clearance lights, it cuts way down on power consumption, they are brighter, and will last for decades.
Try calling Jerry Hamm Chevrolet, they should be able to take care of you.

[swebster]

Originally Posted by wpapke

I'm beginning to think i should have bought a new winnebago or something.

Don't think for a second that a "new" motorhome of any brand will be trouble free. Many owners of new motorhomes are amazed at how often (and long) it takes to work the kinks out of a new motorhome. The joke in the RV Biz is that the dealer is the last ten feet of the production line.

These are complex machines and not everything works all of the time. Especially on a Classic like yours. I spent almost a year "under" mine...but now things are reliable and work (most of the time) and I get to drive a true classic for far less than the payments on a new Winnie.

Hang in there! It will get better.