Overdrive for C30x ?

[Roy Gardiner]

Anyone know if an overdrive is available for these vehicles?

After a couple of hundred mile run at the weekend I can confirm the need for one more ratio 'up top' would solve a lot of our noise and fuel consumption woes on the open road....

Do I remember someone mentioning the manufacturer of the transfer box ?? I guess they would be able to supply/advise if one was made...

Roy

[lindenengineering]

Roy
Since the overdrive transmission (sorry gearbox) for the diesel Pinz and the 5 speed 1:1 box for the 710 series are of the same genre, there is a distinct possibility that you could replace the 4 speed for an O/D unit with some simple changes.
Since the Volvo employs the same ZF box (4 speed version) the adaption of the Pinz 5 speed either in 1:1 form or O/D would only mean a bell housing interchange and shift tower selector assembly from the existing 4 speeder plus a fill plug change.
The big "mechanic" question mark I have not yet solved is the ability to slide the Volvo T /case onto the gearbox output shaft and secure it to the maincase in "either direction".
Fortunately I am in the process of breaking down a C series for parts so I may be in the "knowledge" sooner than I thought.
I will let you know.
By the way the cost of an O/D box off the shelf is not cheap but overall its probably cheaper than fannying around with adaptors etc.
If there is a question mark on suitability the only one I can yet come up with is whether the existing ratios have the Volvo engine's torque curve compatability. After all you still need to try to win the traffic lights Grand Prix against some vehicles!

[Philip Raymond]

No OE overdrive made. Clearly with the state of oil today, an overdrive is of great benefit. Along with relief to the wallet an overdrive would add longevity miles, reduce maintenance, and drop the noise by a factor of 6 -12db at 55-65 mph (actual 303 spectral analysis and data that I’ve tested for).

Given enough money and time one can almost solve any problem, the “over-drive nut” is one tough atom to crack. Three solutions seem obvious a transmission change and or t-case swap. However spend a little more time with the tranny and t-cases, in and out of the vehicle, and you’ll discover that the wily Volvo engineers literally “shoe horned” power plant and drive train into the vehicle.

If you were able to find a ZF S5-14 to swap out for your S4-14 you would then want to change the fifth gear from a 1:1 to 1:. 75 or some overdrive ratio. ZF U.S considers all of this “grey market” and runs away from it faster than s--- going through a goose relegating it to a small ZF shop in Germany who has no interest and or motivation to help out. This “little” amount of info above took months to eek out of ZF. There are supposedly three or more renditions of the ZF 5 speed (Diesel Pinz?, Maseratti Biturbo, Iveco, Itialian Scam,and Volvo 304/306 tgb13/20) but no knowledge about the actual bolt-up nature of the tranny to the bell housing or the correct gearing. Perhaps an enterprising “gear–master” can figure this all out.

Next, assume you “cure cancer” and solve the transmission gear problems and availability, you need to closely look how much room you will need as the drive shaft emergency brake drum has very little, to no room, to move rearward without removing the center frame cross member and the secondary vacuum reservoir.

Clause of the Volvo/Inventor Dakar team has come up with a different design. Using modifications to the Volvo transfer case. Using this novel approach, he also solves the problem with the main weakness of the Volvo transfer case (the back star plate) by adding a set of straight cut gears directly in back of the T-case using the PTO output as part of an overdrive unit. I think there may be a unit or two available for something in the $8k U.S. Don’t forget that this is a constant (not swticheable) overdrive, and one with straight cut gears vs, helical adding back to the audio equation with more noise. Also you ‘d need to do the complete drive train ratios to see where it puts you “rpm vs. mph” and it’s impact on both your high and low end. Lastly, you’ll loose winch drive access from the PTO.

Other alternatives are different transmission, however the OE ZF is a tiny sucker and you’ll introduce adapter plates and extra length that you have to make up forward or rearward. Add a different transmission and then you’ll need to get real creative about how you’ll shift gears as the shift tower is a few feet behind you. It does get challenging and interesting re-doing the shift linkage and actual shift rail interface to work as it was originally engineered. Once more, with some determination, creativity and unfortunately lots of money and time it’s a solvable problem but not one of the easier challenges to attack. Perhaps as more Volvo’s become available there will be enough “critical mass” for someone to engineer a solution and defray the costs against multiple units similar to the Pinz’s, However given the “tinkerer nature” of most Volvo owners, not many will agree to a solution or pricing hence a compromised market. Finally just from a “raw unit analysis” it probably will not happen considering the limited run and total unit cap of Volvo’s as compared to an 8-15X + multiple you see with Pinz and Mog opportunities.

These Volvo’s are truly a “labor of love”. Good luck though on your quest.

Cheers,

[Roy Gardiner]

Thanks guys for your considered replies, in the face of the inexplicable (ie response from ZF) and the unobtainable (5 speed Pinz gearbox) I wonder if the answer may lie in a complete engine/box/tfr box swap...

Dennis - Have you looked at a Range Rover unit complete swap??

As I've mentioned before here I knew a chap who had a Rangey gearbox & tfr box in his C306 behind a Japanese diesel, so there must be room for the plot to fit, RichardDover has measured the V8 and it will go apparently...

Strangely I was offered a complete V8/Auto Rangey yesterday with LPG conversion for £650 (about a thousand dollars-ish) they can't give 'em away over here with fuel at £4.50+ ($6.50 approx) per UK gallon now.

Phillip - Did you check the decibels on a C3 with the ghastly mechanical fan disconnected perchance?

Roy

[Philip Raymond]

Roy,

You jumped to the next rational and logical step…..a “heart lung transplant”. There are a variety of approaches and one can “skin this cat” many ways. Again not a trivial task or one for the faint hearted, mechanically speaking. Key considerations are engine accessibility. Yes the “dog house” will take a V8,…. just can you service the engine? V8 or not, one needs to consider the primary drive axis as the B30 is offset, so you can start looking at straight 6’s but need to be sensitive to are they leftie or righties and actual engine length vs. displacement and the resulting cascade of changes this engine swap brings to the enterprise. For, as we spoke in the earlier posting of rear drive train constraints moving the engine forward introduces probable compressed front axle interference with any engine pan that protrudes further then the stock configuration. To force the compression and evaluate the possibilities we jumped some Volvos at Glamis and Moab, one needs to pay attention to the height of any engine transplant and mandate a rear oil sump.

When considering engine height you need to evaluate how increased the top end heat will be should you want to avoid the crashing front axle engine dance. Doghouse configurations are notorious for stagnant flows and hot spots. You can instrument the engine compartment with thread tufts and mount a video camera in different locations to examine the flow for a variety of speed configurations. You’ll see some fun stuff. Any engine change forward will get us back to our old cooling friend, either in increased BTU/displacement for larger CID engines or the simple vanquishing of the OE mechanical fan assembly. Cooling is an engineering 1st order constraint. There really is no easy or simple way to increase the mean cooling volume for static and realistic operational BTU loading unless your willing to do some substantive sheet metal and vehicle crash integrity modifications never mind those extreme situations when you need max cfm through and over all engine-cooling variables. Simple wind tunnel testing can yield some improvements to maximize cooling while avoiding costly body and mechanical machinations.

Two final things regarding your questions and relative to engine /tranny/xfer swaps. If you hunt around you’ll find one of the older LR series Xfer cases as being a close cousin to the Volvo xfer case and with some creative engineering can generally swap in and perhaps, with a bit more creativity, can alter the gearing to get a fixed OD. However it is fixed thereby effecting all gearing and changing the torque/rpm/load profile. What’s not fixed in this equation is the cost! Again most of these type efforts are “first through the fire prototypes” with their incumbent malaises… rife with infinite tweaking, testing, evaluating and versioning. Quite painful at times!!!

Send me your email via the private posting on this group and I’ll send you the results of our spectral analysis of the C3’s with some surprising and pleasing results regarding your audio curiosities. The data needs to be updated with some new data for the C3-series 8931 vehicle options (you’ll find your vehicle options stricken in one or many of the bottom boxes on the nomenclature plate on the passenger side outside facing dash stub) The chart and data is for your personal use only, it is proprietary data, copyrighted and reflects our work product and efforts.

Cheers,

[Roy Gardiner]

Before launching into a 'heart lung transplant' (!) I'll start with the NVH reduction (Noise,Vibration,Harshness) program Phillip.

As the C3 was bought to provide a basis for a world trip offroad camper, with high roadmileage planned, we need to make some basic improvements first, though the weekends offroad testing proved that the offroad perfromance needs no improvement!.

I'll start doing a bit of research on the required drivetrain/gearing to reach my optimum road-going criteria:

Cruising speed of 70mph for European motorways
'Normal' motorcaravan NVH levels
As near 20mpg as posible on LPG

I should add that to achieve the above the plan includes removal of the standard 1314 rear 'brick'/box (and 850Kgs/1900 lbs!) and replacement with a hi/lo camper body in foam/GRP laminate.

Owing to the relative scarcity of the C303/TGB1111 diffs I'd like to stay with the 1314 axles/diffs if possible - we'll see.

Roy

p.s. My last offroad project build - small block Chevy engined convertible Range Rover, so not too daunted by shoe-horning a std. RR drivetrain on LPG under a C3.

[Philip Raymond]

Roy,

Again good thinking and a solid strategy. After the initial C303 check out unless you are a “Strapping Swedish Youth” or a masochist …ergonomics NVH comes into play dramatically. Although not Spartan (military like) in it’s original design concept and for it’s time, driving hundreds of miles a day in the Volvo without mitigating, noise, drivability (power steering, cruise control, et. etc.), over all cab comfort and of course gearing and cost effective motoring can be taxing in many ways. I once drove 1,000 miles in one sitting in one full day, unimagineable without attending to NVH as you so aptly outlined. I applaud your logic and direction. Do your cooling/cfm homework and punt the mechanical fan along with finding the quieter tires and you’ll be very pleasantly surprised.

Your laminate replacement box approach is also a good idea. In the U.S there is a product called NidaCore which is very strong and lightweight and insulation can be bonded to the surface along with other materials if need be. Also the technology and applications has evolved (primarily used in high end nautical applications) that one can move from working with individual sheets to having a complete box fabricated with NidaCore, cabinets etc. A 1316,1314 box similar dimension replacement would be in the order of 300-350 lbs as compared to the robustly built and very heavy OE box of 1900-2200 lbs.

Of course a next step (but theoretically realistic) is to approach it from a carbon fiber composite with a complete autoclaved box (similar to the manufacturing process used in aeronautical blended body airframe manufacturing) that would be probably yet another 50% lighter from the Nida Core and a 1000% heavier in delivery cost. But you’d be the only kid on the block with one …talk about bling!!!

Clearly you have that engine expertise and now-how so good luck, do a quick few calculations thow for cooling needs. Unless you are into some serious body work you have a fixed and hard total cooling surface area/cfm ceiling to work with.

Cheers,

[Roy Gardiner]

Phillip,

Yes, I know of the material you mentioned as I believe its used by the
folks at Earthroamer:

http://www.earthroamer.com/main_truck/v ... cture.html

We will make the mould plug (basic shape) in our workshop and I have
lined up a boat builder to make the mould and produce the first shell in the GRP/foam laminate material, which he uses extensively in his (£1.5m!) yachts.

As for carbon fibre, he's recommended using a stranded version for structural reinforcement in those areas where we've traditionally fitted steel tubing roll cages...same strength for minimal weight, but we will still incorporate a main hoop for the cab occupants (having been grateful for them quite often in the past!).

Power steering will be a development made easier if we do use a Rover V8 as they come with power steering pump fitted - are you aware of a power steering box that fits the C3 installation?

However, with a vast reduction in vehicle weight and the use of modern radials the need for power steering may be significantly reduced.
I'm a great believer in the 'Keep It Simple' development school, wasn't it Boss Kettering that said "parts left out cause no service problems" (rough quote).

Cooling - If we do use the all-aluminium-alloy Rover V8 (thanks for giving us one of the greatest engines the UK has ever had Buick!) cooling will not be a problem, even with a std. rad as these engine run very cool as the heat dissipation is excellent, but we will fit the 3" rad as a matter of course because the application will include plenty of slow speed (eg desert) clambering around.

Roy